Publications

ASM deficiency in Niemann-Pick disease type A results in aberrant cellular accumulation of sphingomyelin, neuroinflammation, neurodegeneration, and early death. There is no available treatment because enzyme replacement therapy cannot surmount the blood-brain barrier (BBB). Nanocarriers (NCs) targeted across the BBB via transcytosis might help; yet, whether ASM deficiency alters transcytosis remains poorly characterized. We investigated this using model NCs targeted to intracellular adhesion molecule-1 (ICAM-1), transferrin receptor (TfR), or plasmalemma vesicle-associated protein-1 (PV1) in ASM-normal vs. ASM-deficient BBB models. Disease differentially changed the expression of all three targets, with ICAM-1 becoming the highest. Apical binding and uptake of anti-TfR NCs and anti-PV1 NCs were unaffected by disease, while anti-ICAM-1 NCs had increased apical binding and decreased uptake rate, resulting in unchanged intracellular NCs. Additionally, anti-ICAM-1 NCs underwent basolateral reuptake after transcytosis, whose rate was decreased by disease, as for apical uptake. Consequently, disease increased the effective transcytosis rate for anti-ICAM-1 NCs. Increased transcytosis was also observed for anti-PV1 NCs, while anti-TfR NCs remained unaffected. A fraction of each formulation trafficked to endothelial lysosomes. This was decreased in disease for anti-ICAM-1 NCs and anti-PV1 NCs, agreeing with opposite transcytosis changes, while it increased for anti-TfR NCs. Overall, these variations in receptor expression and NC transport resulted in anti-ICAM-1 NCs displaying the highest absolute transcytosis in the disease condition. Furthermore, these results revealed that ASM deficiency can differently alter these processes depending on the particular target, for which this type of study is key to guide the design of therapeutic NCs.© 2023. Controlled Release Society.

JTD Keywords: asm deficiency, blood-brain barrier, delivery, determines, drug, endocytosis, enzymes, icam-1, lysosomal storage disease, mechanisms, nanoparticles, natural-history, niemann-pick disease type a, pv-1, receptor-mediated transcytosis, trafficking, transferrin receptor, Asm deficiency, Blood–brain barrier, Drug nanocarriers, Icam-1, Icam-1-targeted nanocarriers, Lysosomal storage disease, Niemann-pick disease type a, Pv-1, Receptor-mediated transcytosis, Transferrin receptor

Clathrin-mediated endocytosis (CME) is an essential cellular process, conserved among eukaryotes. Yeast constitutes a powerful genetic model to dissect the complex endocytic machinery, yet there is a lack of specific pharmacological agents to interfere with CME in these organisms. TL2 is a light-regulated peptide inhibitor targeting the AP2-β-adaptin/β-arrestin interaction and that can photocontrol CME with high spatiotemporal precision in mammalian cells. Here, we study endocytic protein dynamics by live-cell imaging of the fluorescently tagged coat-associated protein Sla1-GFP, demonstrating that TL2 retains its inhibitory activity in S. cerevisiae spheroplasts. This is despite the β-adaptin/β-arrestin interaction not being conserved in yeast. Our data indicate that the AP2 α-adaptin is the functional target of activated TL2. We identified as interacting partners for the α-appendage, the Eps15 and epsin homologues Ede1 and Ent1. This demonstrates that endocytic cargo loading and sensing can be executed by conserved molecular interfaces, regardless of the proteins involved.© 2023 The Author(s).

JTD Keywords: adapters, alpha-appendage, azobenzene, cross-linker, mechanism, peptides, proteins, receptor, trafficking, Actin polymerization, Biochemistry, Biological sciences, Cell biology, Molecular biology, Natural sciences

Polymeric spherical nucleic acids comprise pH-sensitive, polymer-conjugated oligonucleotides that self-assemble into nanoparticles with the ability to escape endosomes, overcoming a major obstacle in nucleic acid delivery.

JTD Keywords: c9orf72, cellular uptake, dna, encapsulation, expansion, ph, stability, trafficking, vesicles, Hexanucleotide repeat

Cells are subjected to multiple mechanical inputs throughout their lives. Their ability to detect these environmental cues is called mechanosensing, a process in which integrins play an important role. During cellular mechanosensing, plasma membrane (PM) tension is adjusted to mechanical stress through the buffering action of caveolae; however, little is known about the role of caveolae in early integrin mechanosensing regulation. Here, we show that Cav1KO fibroblasts increase adhesion to FN-coated beads when pulled with magnetic tweezers, as compared to wild type fibroblasts. This phenotype is Rho-independent and mainly derived from increased active b1-integrin content on the surface of Cav1KO fibroblasts. FRAP analysis and endocytosis/recycling assays revealed that active b1-integrin is mostly endocytosed through the CLIC/GEEC pathway and is more rapidly recycled to the PM in Cav1KO fibroblasts, in a Rab4 and PM tension-dependent manner. Moreover, the threshold for PM tension-driven b1-integrin activation is lower in Cav1KO MEFs than in wild type MEFs, through a mechanism dependent on talin activity. Our findings suggest that caveolae couple mechanical stress to integrin cycling and activation, thereby regulating the early steps of the cellular mechanosensing response.© 2022, Lolo et al.

JTD Keywords: adhesion, alpha-v-beta-3, cell, integrin activation, internalization, kinase, mechanosensing, mediated endocytosis, mouse, stiffness, talin, trafficking, Cell biology, Integrin activation, Integrin recycling, Mechanosensing, Membrane tension, Mouse

Treatment of neurological lysosomal storage disorders (LSDs) are limited because of impermeability of the blood-brain barrier (BBB) to macromolecules. Nanoformulations targeting BBB transcytosis are being explored, but the status of these routes in LSDs is unknown. We studied nanocarriers (NCs) targeted to the transferrin receptor (TfR), ganglioside GM1 or ICAM1, associated to the clathrin, caveolar or cell adhesion molecule (CAM) routes, respectively. We used brain endothelial cells and mouse models of acid sphingomyelinase-deficient Niemann Pick disease (NPD), and postmortem LSD patients' brains, all compared to respective controls. NC transcytosis across brain endothelial cells and brain distribution in mice were affected, yet through different mechanisms. Reduced TfR and clathrin expression were found, along with decreased transcytosis in cells and mouse brain distribution. Caveolin-1 expression and GM1 transcytosis were also reduced, yet increased GM1 levels seemed to compensate, providing similar NC brain distribution in NPD vs. control mice. A tendency to lower NHE-1 levels was seen, but highly increased ICAM1 expression in cells and human brains correlated with increased transcytosis and brain distribution in mice. Thus, transcytosis-related alterations in NPD and likely other LSDs may impact therapeutic access to the brain, illustrating the need for these mechanistic studies.Copyright © 2022 Elsevier B.V. All rights reserved.

JTD Keywords: acid sphingomyelinase, antibody-affinity, blood -brain barrier, drug-delivery, icam-1-targeted nanocarriers, in-vivo, mediated endocytosis, model, neurological diseases, niemann-pick, targeted nanocarriers, trafficking, transcytosis pathways, Blood-brain barrier, Central-nervous-system, Lysosomal storage disorders, Neurological diseases, Targeted nanocarriers, Transcytosis pathways

Nanomedicine emerged some decades ago with the hope to be the solution for most unmet medical needs. However, tracking materials at nanoscale is challenging to their reduced size, below the resolution limit of most conventional techniques. In this context, we propose the use of direct stochastic optical reconstruction microscopy (dSTORM) to study time stability and cell trafficking after transfection of oligopeptide end-modified poly(?-aminoester) (OM-pBAE) nanoparticles. We selected different combinations of cationic end oligopeptides (arginine - R; histidine - H; and lysine - K) among polymer libraries, since the oligopeptide combination demonstrated to be useful for different applications, such as vaccination and gene silencing. We demonstrate that their time evolution as well as their cell uptake and trafficking are dependent on the oligopeptide. This study opens the pave to broad mechanistic studies at nanoscale that could enable a rational selection of specific pBAE nanoparticles composition after determining their stability and cell trafficking.© 2022 The Authors. ChemMedChem published by Wiley-VCH GmbH.

JTD Keywords: cancer nanomedicine, cell trafficking, delivery, direct stochastic optical reconstruction microscopy (dstorm), nanoparticle stability, poly(beta-aminoester) nanoparticles, Direct stochastic optical reconstruction microscopy (dstorm), Poly(?-aminoester) nanoparticles, Poly(beta-amino ester)s, Poly(β-aminoester) nanoparticles

Since their invention about two decades ago, super-resolution microscopes have become a method of choice in cell biology. Owing to a spatial resolution below 50 nm, smaller than the size of most organelles, and an order of magnitude better than the diffraction limit of conventional light microscopes, superresolution microscopy is a powerful technique for resolving intracellular trafficking. In this review we discuss discoveries in endocytosis and phagocytosis that have been made possible by super-resolution microscopy – from uptake at the plasma membrane, endocytic coat formation, and cytoskeletal rearrangements to endosomal maturation. The detailed visualization of the diverse molecular assemblies that mediate endocytic uptake will provide a better understanding of how cells ingest extracellular material.

JTD Keywords: Endocytosis, Endosomes, Organelles, Super-resolution microscopy, Trafficking

Endocytosis and vesicular trafficking are cellular processes that regulate numerous functions required to sustain life. From a translational perspective, they offer avenues to improve the access of therapeutic drugs across cellular barriers that separate body compartments and into diseased cells. However, the fact that many factors have the potential to alter these routes, impacting our ability to effectively exploit them, is often overlooked. Altered vesicular transport may arise from the molecular defects underlying the pathological syndrome which we aim to treat, the activity of the drugs being used, or side effects derived from the drug carriers employed. In addition, most cellular models currently available do not properly reflect key physiological parameters of the biological environment in the body, hindering translational progress. This article offers a critical overview of these topics, discussing current achievements, limitations and future perspectives on the use of vesicular transport for drug delivery applications.

JTD Keywords: Cellular vesicles, Vesicle fusion, Fission and intracellular trafficking, Drug delivery systems and nanomedicines, Transcytosis and endocytosis of drugs carriers, Disease effects on vesicular trafficking, Drug effects on vesicular trafficking, Role of the biological environment