Revolutionary fluorescent cholesterol probes now provide scientists with the ability to observe cholesterol movement and distribution in living cells with remarkable clarity. By fusing computer modeling with live-cell imaging, researchers have discovered how various probe designs affect the behavior of cholesterol probes. These innovative tools may help us understand how cholesterol imbalances contribute to diseases like Alzheimer’s and other neurodegenerative disorders, thus supporting the development of medications that can influence lipid activity and potentially lead to new therapies or prevention methods.
The quest for solutions to Alzheimer’s disease and other neurodegenerative conditions is a critical focus in brain research. Maciej J. Stawikowski, Ph.D., an assistant professor of chemistry and biochemistry at Florida Atlantic University’s Charles E. Schmidt College of Science, believes understanding the movement of cholesterol and other lipids in cells could be pivotal.
“It’s widely recognized that there is a connection between lipids and Alzheimer’s,” stated Stawikowski, who is also associated with the FAU Stiles-Nicholson Brain Institute. “An imbalance of lipids might cause the development of amyloid plaques—large protein aggregates that hinder cell functions, which is a signature characteristic of Alzheimer’s.”
His research group, which includes Qi Zhang, Ph.D., an associate professor in the FAU Department of Chemistry and Biochemistry and an FAU Stiles-Nicholson Brain Institute member, is dedicated to creating advanced tools for studying the connection between lipids and cell functions.
Cholesterol plays an essential role in cellular membranes, contributing to hormone synthesis, stabilizing membranes, and facilitating signaling. However, disruptions to cholesterol movement among cellular compartments could be linked to Alzheimer’s and other neurodegenerative illnesses. To explore this, Stawikowski and his team have devised cutting-edge fluorescent cholesterol probes (CNDs) specifically crafted to monitor cholesterol within cellular membranes.
A recent study published in Scientific Reports showcases how CND probes can effectively visualize cholesterol in living cells. By integrating computer simulations with live-cell imaging, the researchers have identified how various probe designs impact cholesterol behavior within cells.
These pioneering probes stand to deepen our understanding of how disruptions in cholesterol levels may lead to Alzheimer’s and other neurodegenerative diseases. By gaining insight into cholesterol’s role in amyloid plaque formation and cellular signaling, researchers might create drugs that can influence lipid activity, potentially paving the way for new treatments or preventive approaches.
“With these probes, we can now visualize cholesterol movement and distribution in live cells with unprecedented detail,” Stawikowski remarked, who is the senior author of the study.
The CND probes utilize a 1,8-naphthalimide (ND) framework, notable for its exceptional fluorescence characteristics, including significant Stokes shifts and responsiveness to environmental factors. This innovative configuration allows for modular customization, enabling scientists to adapt the probes with various head groups and linkers to suit specific experimental needs. Results indicate that altering head groups or linkers can improve the probes’ sensitivity and targeting capacity.
These probes can be categorized into three different types. Neutral probes tend to group together easily, although their cellular absorption is somewhat constrained. Conversely, charged probes exhibit better solubility and interaction with cell membranes. Probes enriched with hydroxyl groups further enhance hydrogen bonding and lipid interactions, making them particularly suitable for analyzing membrane dynamics.
Moreover, some CND probe variants are sensitive to pH fluctuations, enabling researchers to monitor cholesterol movement in organelles with different acidity levels, such as lysosomes and lipid droplets. Compared to conventional cholesterol probes, these new tools provide enhanced fluorescence capabilities and more precise monitoring of cholesterol dynamics, yielding richer insights into cellular mechanisms.
“Cholesterol is vital for brain function, but its misregulation might significantly influence disease development,” asserted Stawikowski. “Our novel tools offer an insightful perspective on how cholesterol affects cellular processes and could help pinpoint therapeutic targets for conditions like Alzheimer’s.”
The fluorescent cholesterol probes developed by the research team hold promise for applications beyond Alzheimer’s, with potential uses in membrane biology, lipid dynamics, and drug delivery. By merging experimental techniques with computational simulations, the FAU team has established a foundation for creating more effective fluorescent cholesteryl probes applicable to a variety of lipid-related conditions.
These versatile probes can be customized for various research demands, representing a significant advancement in deciphering cholesterol’s role in cellular health and disease.
Co-authors of the study include Zhang; Vincente Rubio, Ph.D.; Nicholas McInchak; Genesis Fernandez; Dana Benavides; Diana Herrera; and Catherine Jimenez; all FAU graduates; alongside Haylee Mesa, a doctoral student at the FAU Stiles-Nicholson Brain Institute; and Jonathan Meade, a graduate and laboratory technician from FAU.
