FRET (Information Maximized FRET) for Multipoint Single-Molecule Structural Analysis.

Understanding the structure of biomolecules is vital for deciphering their roles in biological systems. Single-molecule techniques have emerged as alternatives to conventional ensemble structure analysis methods for uncovering new biology in molecular dynamics and interaction studies, yet only limited structural information could be obtained experimentally. Here, we address this challenge by introducing FRET, a one-pot method that allows 3D profiling of individual molecules using two-color FRET measurements.

Preparation of chaperone-loaded neural stem cell-derived extracellular vesicles to reduce protein aggregation in Huntington's disease cellular models.

Here, we present a protocol using genetic engineering techniques to prepare small extracellular vesicles (sEVs) enriched in the chaperone protein DNAJB6. We describe steps to prepare cell lines overexpressing DNAJB6, followed by the isolation and characterization of sEVs from cell conditioned media. Further, we describe assays to examine effects of DNAJB6-loaded sEVs on protein aggregation in Huntington's disease cellular models.

DNAJB6-Containing Extracellular Vesicles as Chaperone Delivery Systems: A Proteomic Analysis.

Cell-derived extracellular vesicles (EVs) are effectors of cell-to-cell communication that are in the spotlight as promising candidates for in vivo drug delivery because of their ability to enter cells and deliver cargo. For example, proteins of interest can be loaded into EVs to mediate protein transfer into target cells. To determine causality between EV content and function, which is also important to assess the clinical safety of EVs, it is crucial to comprehensively characterize their complete molecular composition.

DNAJB6b-enriched small extracellular vesicles decrease polyglutamine aggregation in and models of Huntington disease.

Huntington disease (HD) is a devastating neurodegenerative disorder characterized by aggregation of huntingtin (HTT) protein containing expanded polyglutamine (polyQ) tracts. DNAJB6, a member of the DNAJ chaperone family, was reported to efficiently inhibit polyQ aggregation , in cell models, and in flies, xenopus, and mice. For the delivery of exogenous DNAJB6 to the brain, the DNAJB6 needs to be protected against (enzymatic) degradation and show good penetration into brain tissue.

Heparan sulfate proteoglycan-mediated dynamin-dependent transport of neural stem cell exosomes in an in vitro blood-brain barrier model.

Drug delivery to the brain is greatly hampered by the presence of the blood-brain barrier (BBB) which tightly regulates the passage of molecules from blood to brain and vice versa. Nanocarriers, in which drugs can be encapsulated, can move across the blood-brain barrier (BBB) via the process of transcytosis, thus showing promise to improve drug delivery to the brain. Here, we demonstrate the use of natural nanovesicles, that is, exosomes, derived from C17.

Endocytosis of Extracellular Vesicles and Release of Their Cargo from Endosomes.

Extracellular vesicles (EVs), such as exosomes, can mediate long-distance communication between cells by delivering biomolecular cargo. It is speculated that EVs undergo back-fusion at multivesicular bodies (MVBs) in recipient cells to release their functional cargo. However, direct evidence is lacking.