Teletherapy, AAC & COVID-19: the experiences of speech language pathologists providing teletherapy during a global pandemic.

The COVID-19 pandemic required many speech-language pathologists (SLPs) to transition to teletherapy service delivery. This study was designed to explore the experiences and perceptions of SLPs who made this transition with children with disabilities who used aided augmentative and alternative communication (AAC). Semi-structured interviews were conducted virtually with 10 SLPs who provided regular teletherapy services to children who used AAC during but not before the pandemic. Interview transcripts were analyzed thematically using immersion, reduction, and constant comparison to understand SLP experiences and perceptions individually and across the group. Results reveal that despite the challenges faced transitioning to teletherapy, there were benefits. Furthermore, many of the participating SLPs developed successful strategies and solutions for the challenges they faced. Participants in this study highlighted the unique and important role that caregivers and parents played in the success of the teletherapy they provided. This study suggests that SLPs, caregivers, and children demonstrated resilience in the face of a large-scale, unforeseen change. SLPs consistently reported the ability to maintain continuity of care during a stressful transition period, while meeting the unique needs of the children who used AAC they served.

Human endothelial cell-derived exosomal microRNA-99a/b drives a sustained inflammatory response during sepsis by inhibiting mTOR expression.

The pathophysiology of sepsis and its accompanying hyper-inflammatory response are key events that lead to multi-organ failure and death. A growing body of literature now suggests that the vascular endothelium plays a critical role in driving early events of sepsis progression. In this study, we demonstrate how endothelial-derived exosomes contribute to a successive pro-inflammatory phenotype of monocytes. Exosomes isolated from S. aureus infected endothelial cells drive both CD11b and MHCII expression in monocytes and contribute dysregulated cytokine production. Conversely, healthy endothelial exosomes had no major effect. microRNA (miRNA) profiling of exosomes identified miR-99 upregulation which we hypothesised as driving this phenotypic change through mechanistic target of rapamycin (mTOR). Knockdown of mTOR with miR-99a and miR-99b mimetics in S. aureus infected monocytes increased IL-6 and decreased IL-10 production. Interestingly, inhibition of miRNAs with antagomirs has the opposing effect. Collectively, endothelial exosomes are driving a pro-inflammatory phenotype in monocytes through dysregulated expression of miR-99a and miR-99b.

Molecular Cross-Talk between Integrins and Cadherins Leads to a Loss of Vascular Barrier Integrity during SARS-CoV-2 Infection.

The vascular barrier is heavily injured following SARS-CoV-2 infection and contributes enormously to life-threatening complications in COVID-19. This endothelial dysfunction is associated with the phlogistic phenomenon of cytokine storms, thrombotic complications, abnormal coagulation, hypoxemia, and multiple organ failure. The mechanisms surrounding COVID-19 associated endotheliitis have been widely attributed to ACE2-mediated pathways. However, integrins are emerging as possible receptor candidates for SARS-CoV-2, and their complex intracellular signaling events are essential for maintaining endothelial homeostasis. Here, we showed that the spike protein of SARS-CoV-2 depends on its RGD motif to drive barrier dysregulation by hijacking integrin αVß3, expressed on human endothelial cells. This triggers the redistribution and internalization of major junction protein VE-Cadherin which leads to the barrier disruption phenotype. Both extracellular and intracellular inhibitors of integrin αVß3 prevented these effects, similarly to the RGD-cyclic peptide compound Cilengitide, which suggests that the spike protein-through its RGD motif-binds to αVß3 and elicits vascular leakage events. These findings support integrins as an additional receptor for SARS-CoV-2, particularly as integrin engagement can elucidate many of the adverse endothelial dysfunction events that stem from COVID-19.

SARS-CoV-2 uses major endothelial integrin αvß3 to cause vascular dysregulation in-vitro during COVID-19.

The unprecedented global COVID-19 pandemic has prompted a desperate international effort to accelerate the development of anti-viral candidates. For unknown reasons, COVID-19 infections are associated with adverse cardiovascular complications, implicating that vascular endothelial cells are essential in viral propagation. The etiological pathogen, SARS-CoV-2, has a higher reproductive number and infection rate than its predecessors, indicating it possesses novel characteristics that infers enhanced transmissibility. A unique K403R spike protein substitution encodes an Arg-Gly-Asp (RGD) motif, introducing a potential role for RGD-binding host integrins. Integrin αVß3 is widely expressed across the host, particularly in the endothelium, which acts as the final barrier before microbial entry into the bloodstream. This mutagenesis creates an additional binding site, which may be sufficient to increase SARS-CoV-2 pathogenicity. Here, we investigate how SARS-CoV-2 passes from the epithelium to endothelium, the effects of αVß3 antagonist, Cilengitide, on viral adhesion, vasculature permeability and leakage, and also report on a simulated interaction between the viral and host protein in-silico.

Targeting Internalized Staphylococcus aureus Using Vancomycin-Loaded Nanoparticles to Treat Recurrent Bloodstream Infections.

The bacterial pathogen Staphylococcus aureus is a leading cause of bloodstream infections, where patients often suffer from relapse despite antibiotic therapy. Traditional anti-staphylococcal drugs display reduced effectivity against internalised bacteria, but nanoparticles conjugated with antibiotics can overcome these challenges. In the present study, we aimed to characterise the internalisation and re-emergence of S. aureus from human endothelial cells and construct a new formulation of nanoparticles that target intracellular bacteria. Using an in vitro infection model, we demonstrated that S. aureus invades and persists within endothelial cells, mediated through bacterial extracellular surface adhesion, Fibronectin-binding protein A/B. After internalising, S. aureus localises to vacuoles as determined by transmission electron microscopy. Viable S. aureus emerges from endothelial cells after 48 h, supporting the notion that intracellular persistence contributes to infection relapses during bloodstream infections. Poly lactic-co-glycolic acid nanoparticles were formulated using a water-in-oil double emulsion method, which loaded 10% vancomycin HCl with 82.85% ± 12 encapsulation efficiency. These non-toxic nanoparticles were successfully taken up by cells and demonstrated a biphasic controlled release of 91 ± 4% vancomycin. They significantly reduced S. aureus intracellular growth within infected endothelial cells, which suggests future potential applications for targeting internalised bacteria and reducing mortality associated with bacteraemia.

A new perspective in sepsis treatment: could RGD-dependent integrins be novel targets?

Sepsis is a life-threatening condition caused by the response of the body to an infection, and has recently been regarded as a global health priority because of the lack of effective treatments available. Vascular endothelial cells have a crucial role in sepsis and are believed to be a major target of pathogens during the early stages of infection. Accumulating evidence suggests that common sepsis pathogens, including bacteria, fungi, and viruses, all contain a critical integrin recognition motif, Arg-Gly-Asp (RGD), in their major cell wall-exposed proteins that might act as ligands to crosslink to vascular endothelial cells, triggering systemic dysregulation resulting in sepsis. In this review, we discuss the potential of anti-integrin therapy in the treatment of sepsis and septic shock.