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Klymchenko, A.

Publications and source records attributed to Klymchenko, A..

2 recordsLinked to original sources

Endosomal membrane state governs trafficking and cell migration under TFEB control

Transcription Factor EB (TFEB) regulates the biogenesis of lysosomes, which are acidic organelles of the endosomal network. While its role in cellular clearance is well established, the pleiotropic functions of TFEB across diverse cellular processes, as well as its activation in several cancer types, remain incompletely understood. Investigating TFEB in a bladder cancer model, we found that its depletion selectively impaired cell migration and adhesion. This phenotype was associated with the retention of the adhesion molecule integrin {beta}5 (ITG{beta}5), in central intracellular compartments identified as multivesicular bodies (MVBs) upon TFEB knockdown (KD). Mechanistically, TFEB regulated cellular lipid composition and membrane fluidity of acidic endosomes that controlled ITG{beta}5 trafficking. Remarkably, exogenous supplementation with a monounsaturated fatty acid (MUFA) that increased MVB membrane fluidity was sufficient to phenocopy the intracellular trapping of ITG{beta}5 in 2D culture and 3D tumoroids. We further showed that TFEB-dependent maintenance of MVB membrane fluidity relies on ESCRT-0 subcomplex, HGS/Hrs, which retains cholesterol at MVBs. Together, these findings reveal how transcriptional programs shape endosomal membrane states to control cargo trafficking and cell behavior.

cell biology↗

Highly fluorescent biodegradable PLGA nano-carriers allows real-time tracking of individual particles in vivo

Poly(lactic-co-glycolic acid) (PLGA)-based drug formulations are approved for the use in humans, however, the potential of PLGA to design nanoparticles (NPs) and target the central nervous system remains to be exploited. The aim of the current study was design PLGA NPs, loading them with bulky fluorophores thereby increasing single particle fluorescence to a level visible by in vivo microscopy, and investigate their brain biodistribution. We developed, highly fluorescent 70 nm PLGA NPs significantly brighter then quantum dots enabling their visualization by intravital real-time 2-photon microscopy. We found that PLGA NPs coated with pluronic F-68 (PF-68) had a substantially longer plasma half-life than uncoated NPs and were taken up by cerebro-vascular endothelial cells. High resolution confocal microscopy revealed that coated PLGA NPs were present in late endothelial endosomes of cerebral vessels within 1 hour after systemic injection and were more readily taken up by endothelial cells in peripheral organs. The current data suggest that PF-68 coated PLGA NPs are taken up by mouse cerebral and peripheral endothelial cells in vivo. The combination of ultra-bright NPs and in vivo imaging may thus represent a promising approach to reduce the gap between development and clinical application of nanoparticle-based drug carriers.

bioengineering↗