Lipid droplets: biophysics of the first steps of biogenesis

BENJAMÍN CARUSO; PAULA CANDELA MURATORI BREST

Edicion virtual

Congreso; XLIX Reunión Anual SAB; 2021

Sociedad Argentina de Biofisica

"Lipid Droplets" (LDs) are intracellular structures formed by a neutral lipid nucleussurrounded by a single layer of phospholipids (PLs) and proteins. They are recognized askey organelles for intracellular physiology since they are involved in multiple roles withincell biology. Furthermore, they play a role in several diseases (such as dengue, coronavirusand non-viral infections), cancer and obesity. The dynamics of LDs among them varygreatly, but these differences can be accounted for by their processes of assembly anddisassembly. For this reason, it is now considered of key importance to study theirbiogenesis, which occurs in the endoplasmic reticulum (ER) membrane. This work aims tocontribute to this objective from a biophysical approach, focusing on the molecularmechanisms that induce the first stages of formation of LDs, particularly, those whichtrigger the accumulation and budding of triglycerides (TGs) within the ER membranebilayer. For this purpose, we use Langmuir films and Brewster Angle Microscopy to study,on model monolayers, the influence of certain PLs (with different spontaneous curvatures:POPE (-), POPC (0) and LPA (+)) on the stability and topology of the 3D structures formed(“lenses´´), being able to study each lens individually. Thus, we aim to describe theenergetic properties (interfacial tension and rheology) that will predict the accumulationand permanence of the TGs in the interface or their budding as an independent structure,as well as characterize the molecular conditions that predict the accumulation of "blisters"of TGs inside bilayers.