Protein corona and phospholipase activity drive selective accumulation of nanomicelles in atherosclerotic plaques

ApoB-100 and Phosphatidylcholine-specific phospholipase C (PC-PLC) are important contributors to atherosclerosis development. ApoB-100 is the main structural protein of LDL, being directly associated with atherosclerosis plaque generation. PC-PLC is highly expressed in atherosclerosis lesions and contributes to their progression. We show how phosphatidylcholine-coated nanomicelles can be used for specific characterisation of atherosclerosis plaque. Results show that ApoB-100 in the protein corona of the nanomicelle targets the particles to atherosclerotic areas in apolipoprotein E^?/? mice. Furthermore, PC-PLC selectively removes the polar heads from the phospholipid coating of the nanomicelles leading to their accumulation. To fully characterise the behaviour of the nanomicelles, we developed multimodal probes using a nanoemulsion step. Hybrid imaging revealed plaque accumulation of the nanomicelles and colocalisation with PC-PLC expression and ApoB-100 in the plaque. This study shows how protein corona composition and enzyme-driven nanomaterial accumulation can be used for detection of atherosclerosis.     

Switching cell penetrating and CXCR4-binding activities of nanoscale-organized arginine-rich peptides

Arginine-rich protein motifs have been described as potent cell-penetrating peptides (CPPs) but also as rather specific ligands of the cell surface chemokine receptor CXCR4, involved in the infection by the human immunodeficiency virus (HIV). Polyarginines are commonly used to functionalize nanoscale vehicles for gene therapy and drug delivery, aimed to enhance cell penetrability of the therapeutic cargo. However, under which conditions these peptides do act as either unspecific or specific ligands is unknown. We have here explored the cell penetrability of differently charged polyarginines in two alternative presentations, namely as unassembled fusion proteins or assembled in multimeric protein nanoparticles. By this, we have observed that arginine-rich peptides switch between receptor-mediated and receptor-independent mechanisms of cell penetration. The relative weight of these activities is determined by the electrostatic charge of the construct and the oligomerization status of the nanoscale material, both regulatable by conventional protein engineering approaches.     

Survival and Functional Outcomes in Boys with Cerebral Adrenoleukodystrophy with and without Hematopoietic Stem Cell Transplantation

Cerebral adrenoleukodystrophy (CALD) is a rapidly progressing, often fatal neurodegenerative disease caused by mutations in the ABCD1 gene, resulting in deficiency of ALD protein. Clinical benefit has been reported following allogeneic hematopoietic stem cell transplantation (HSCT). We conducted a large multicenter retrospective chart review to characterize the natural history of CALD, to describe outcomes after HSCT, and to identify predictors of treatment outcomes. Major functional disabilities (MFDs) were identified as having the most significant impact on patients’ abilities to function independently and were used to assess HSCT outcome. Neurologic function score (NFS) and Loes magnetic resonance imaging score were assessed. Data were collected on 72 patients with CALD who did not undergo HSCT (untreated cohort) and on 65 patients who underwent transplantation (HSCT cohort) at 5 clinical sites. Kaplan-Meier (KM) estimates of 5-year overall survival (OS) from the time of CALD diagnosis were 55% (95% confidence interval [CI], 42.2% to 65.7%) for the untreated cohort and 78% (95% CI, 64% to 86.6%) for the HSCT cohort overall (P?=?.01). KM estimates of 2-year MFD-free survival for patients with gadolinium-enhanced lesions (GdE⁺) were 29% (95% CI, 11.7% to 48.2%) for untreated patients (n?=?21). For patients who underwent HSCT with GdE⁺ at baseline, with an NFS ≤1 and Loes score of 0.5 to ≤9 (n?=?27), the 2-year MFD-free survival was 84% (95% CI, 62.3% to 93.6%). Mortality rates post-HSCT were 8% (5 of 65) at 100days and 18% (12 of 65) at 1 year, with disease progression (44%; 7 of 16) and infection (31%; 5 of 16) listed as the most common causes of death. Adverse events post-HSCT included infection (29%; 19 of 65), acute grade II-IV graft-versus-host disease (GVHD) (31%; 18 of 58), and chronic GVHD (7%; 4 of 58). Eighteen percent of the patients (12 of 65) experienced engraftment failure after their first HSCT. Positive predictors of OS in the HSCT cohort may include donor-recipient HLA matching and lack of GVHD, and early disease treatment was predictive of MFD-free survival. GdE⁺ status is a strong predictor of disease progression in untreated patients.? This study confirms HSCT as an effective treatment for CALD when performed early. We propose survival without MFDs as a relevant treatment goal, rather than solely assessing OS as an indicator of treatment success.     

In vitro expression of vital virulent genes of clinical and environmental isolates of Cryptococcus neoformans/gattii in endothelial cells of human blood-brain barrier

BackgroundEvaluation of the pathogenesis of clinical and environmental cryptococcal isolates to the central nervous system is necessary for understanding the risk. This study was designed to determine the in vitro expression of six important virulent genes of Cryptococcus neoformans/gattii in Human Brain Microvascular Endothelial cells (hBMEC).MethodsThe hBMEC were infected with Cryptococcus to determine invasion and survival rate at 3, 12 and 24 hours by subsequent colony count of internalized yeasts. The whole RNA of the intracellular Cryptococcus was extracted to quantify the expression of CAP10, PLB1, ENA1, URE1, LAC1, and MATα genes by real-time quantitative PCR for 3 and 12 hours of infection.ResultsInvasion and survival rates were higher in clinical and standard strains of C. neoformans. A significant difference was observed among the clinical and environmental isolates for the expression of CAP10, ENA1, LAC1, MATα and URE1 at 3 hours, and ENA1, LAC1, MATα, PLB1 and URE1 at 12 hours. Clinical isolates showed significant upregulation of all the genes except PLB1, which was higher in environmental isolates. Relative expressions at the two time-points showed statistically significant (P = 0.043) changes for the clinical isolates and no significance (P = 0.063) for environmental isolates.ConclusionThe C. gattii (VGI) isolates showed significantly lower invasion and survival than C. neoformans (VNI, and VNII) irrespective of their sources. Clinical isolates exhibited higher expression for the majority of the virulent genes until 12 hours of infection, probably due to their better adaptation in the host system and enhanced pathogenicity than the environmental counterparts.