Putting the STING back into BH3-mimetic drugs for TP53-mutant blood cancers.

TP53-mutant blood cancers remain a clinical challenge. BH3-mimetic drugs inhibit BCL-2 pro-survival proteins, inducing cancer cell apoptosis. Despite acting downstream of p53, functional p53 is required for maximal cancer cell killing by BH3-mimetics through an unknown mechanism. Here, we report p53 is activated following BH3-mimetic induced mitochondrial outer membrane permeabilization, leading to BH3-only protein induction and thereby potentiating the pro-apoptotic signal. TP53-deficient lymphomas lack this feedforward loop, providing opportunities for survival and disease relapse after BH3-mimetic treatment. The therapeutic barrier imposed by defects in TP53 can be overcome by direct activation of the cGAS/STING pathway, which promotes apoptosis of blood cancer cells through p53-independent BH3-only protein upregulation. Combining clinically relevant STING agonists with BH3-mimetic drugs efficiently kills TRP53/TP53-mutant mouse B lymphoma, human NK/T lymphoma, and acute myeloid leukemia cells. This represents a promising therapy regime that can be fast-tracked to tackle TP53-mutant blood cancers in the clinic.

Epstein-Barr Virus and the Pathogenesis of Diffuse Large B-Cell Lymphoma.

Epstein-Barr virus (EBV), defined as a group I carcinogen by the World Health Organization (WHO), is present in the tumour cells of patients with different forms of B-cell lymphoma, including Burkitt lymphoma, Hodgkin lymphoma, post-transplant lymphoproliferative disorders, and, most recently, diffuse large B-cell lymphoma (DLBCL). Understanding how EBV contributes to the development of these different types of B-cell lymphoma has not only provided fundamental insights into the underlying mechanisms of viral oncogenesis, but has also highlighted potential new therapeutic opportunities. In this review, we describe the effects of EBV infection in normal B-cells and we address the germinal centre model of infection and how this can lead to lymphoma in some instances. We then explore the recent reclassification of EBV+ DLBCL as an established entity in the WHO fifth edition and ICC 2022 classifications, emphasising the unique nature of this entity. To that end, we also explore the unique genetic background of this entity and briefly discuss the potential role of the tumour microenvironment in lymphomagenesis and disease progression. Despite the recent progress in elucidating the mechanisms of this malignancy, much work remains to be done to improve patient stratification, treatment strategies, and outcomes.

Identification of Nanoparticle Properties for Optimal Drug Delivery across a Physiological Cell Barrier.

Nanoparticles (NPs) represent an attractive strategy to overcome difficulties associated with the delivery of therapeutics. Knowing the optimal properties of NPs to address these issues could allow for improved in vivo responses. This work investigated NPs prepared from 5 materials of 3 sizes and 3 concentrations applied to a cell barrier model. The NPs permeability across a cell barrier and their effects on cell barrier integrity and cell viability were evaluated. The properties of these NPs, as determined in water (traditional) vs. media (realistic), were compared to cell responses. It was found that for all cellular activities, NP properties determined in media was the best predictor of the cell response. Notably, ZnO NPs caused significant alterations to cell viability across all 3 cell lines tested. Importantly, we report that the zeta potential of NPs correlates significantly with NP permeability and NP-induced changes in cell viability. NPs with physiological-based zeta potential of -12 mV result in good cell barrier penetration without considerable changes in cell viability.

S100B dysregulation during brain development affects synaptic SHANK protein networks via alteration of zinc homeostasis.

Autism Spectrum Disorders (ASD) are caused by a combination of genetic predisposition and nongenetic factors. Among the nongenetic factors, maternal immune system activation and zinc deficiency have been proposed. Intriguingly, as a genetic factor, copy-number variations in S100B, a pro-inflammatory damage-associated molecular pattern (DAMP), have been associated with ASD, and increased serum S100B has been found in ASD. Interestingly, it has been shown that increased S100B levels affect zinc homeostasis in vitro. Thus, here, we investigated the influence of increased S100B levels in vitro and in vivo during pregnancy in mice regarding zinc availability, the zinc-sensitive SHANK protein networks associated with ASD, and behavioral outcomes. We observed that S100B affects the synaptic SHANK2 and SHANK3 levels in a zinc-dependent manner, especially early in neuronal development. Animals exposed to high S100B levels in utero similarly show reduced levels of free zinc and SHANK2 in the brain. On the behavioral level, these mice display hyperactivity, increased stereotypic and abnormal social behaviors, and cognitive impairment. Pro-inflammatory factors and zinc-signaling alterations converge on the synaptic level revealing a common pathomechanism that may mechanistically explain a large share of ASD cases.

The effect of serum starvation on tight junctional proteins and barrier formation in Caco-2 cells.

Assessing the ability of pharmaceutics to cross biological barriers and reach the site-of-action requires faithful representation of these barriers in vitro. Difficulties have arisen in replicating in vivo resistance in vitro. This paper investigated serum starvation as a method to increase Caco-2 barrier stability and resistance. The effect of serum starvation on tight junction production was examined using transwell models; specifically, transendothelial electrical resistance (TEER), and the expression and localization of tight junction proteins, occludin and zonula occludens-1 (ZO-1), were studied using western blotting and immunofluorescence. Changing cells to serum-free media 2 days post-seeding resulted in TEER readings of nearly 5000 Ω cm2 but the TEER rapidly declined subsequently. Meanwhile, exchanging cells to serum-free media 4-6 days post-seeding produced barriers with resistance readings between 3000 and 4000 Ω cm2, which could be maintained for 18 days. This corresponded to an increase in occludin levels. Serum starvation as a means of barrier formation is simple, reproducible, and cost-effective. It could feasibly be implemented in a variety of pre-clinical pharmaceutical assessments of drug permeability across various biological barriers with the view to improving the clinical translation of novel therapeutics.

Mechanical characterisation of the human dura mater, falx cerebri and superior sagittal sinus.

The cranial meninges have been shown to play a pivotal role in traumatic brain injury mechanopathology. However, while the mechanical response of the brain and its many subregions have been studied extensively, the meninges have conventionally been overlooked. This paper presents the first comparative mechanical analysis of human dura mater, falx cerebri and superior sagittal sinus tissues. Biaxial tensile analysis identified that these tissues are mechanically heterogeneous, in contrast to the assumption that the tissues are mechanically homogeneous which is typically employed in FE model design. A thickness of 0.91 ± 0.05 (standard error) mm for the falx cerebri was also identified. This data can aid in improving the biofidelity of the influential falx structure in FE models. Additionally, the use of a collagen hybridizing peptide on the superior sagittal sinus suggests this structure is particularly susceptible to the effects of circumferential stretch, which may have important implications for clinical treatment of dural venous sinus pathologies. Collectively, this research progresses understanding of meningeal mechanical and structural characteristics and may aid in elucidating the behaviour of these tissues in healthy and diseased conditions. STATEMENT OF SIGNIFICANCE: This study presents the first evaluation of human falx cerebri and superior sagittal sinus mechanical, geometrical and structural properties, along with a comparison to cranial dura mater. To mechanically characterise the tissues, biaxial tensile testing is conducted on the tissues. This analysis identifies, for the first time, mechanical stiffness differences between these tissues. Additionally, geometrical analysis identifies that there are thickness differences between the tissues. The evaluation of human meningeal tissues allows for direct implementation of the novel data to finite element head injury models to enable improved biofidelity of these influential structures in traumatic brain injury simulations. This work also identifies that the superior sagittal sinus may be easily damaged during clinical angioplasty procedures, which may inform the treatment of dural sinus pathologies.

On the association between circulating biomarkers and atherosclerotic calcification in a cohort of arterial disease participants.

BACKGROUND AND AIMS: Atherosclerotic calcification is a powerful predictor of cardiovascular disease. This study aims to determine whether circulating levels of a local/systemic calcification inhibitor or a marker of bone formation correlate with measures of coronary or extracoronary calcification. METHODS AND RESULTS: Clinical computed tomography (CT) was performed on 64 arterial disease participants undergoing carotid and lower extremity endarterectomy. Coronary artery calcium (CAC) scores and volumes were acquired from the CT scans (n = 42). CAC scores and volumes were used to derive CAC density scores. Micro-CT was performed on excised carotid (n = 36) and lower extremity (n = 31) plaques to quantify the volume and volume fraction of extracoronary calcification. Circulating levels of dephospho-uncarboxylated Matrix Gla Protein (dp-ucMGP), fetuin-A, carboxylated and uncarboxylated osteocalcin (ucOC) were quantified using commercial immunoassays. Carotid participant CAC density scores were moderately negatively correlated with plasma dp-ucMGP (rs = -0.592, P = 0.008). A weak negative association was found between CAC scores and %ucOC for all participants (rs = -0.335, P = 0.040). Another weak negative correlation was observed between fetuin-A and the volume of calcification within excised carotid specimens (rs = -0.366, P = 0.031). Despite substantial differences in coronary and extracoronary calcium measurements, the levels of circulating biomarkers did not vary significantly between carotid and lower extremity subgroups. CONCLUSION: Correlations identified between circulating biomarkers and measures of coronary and extracoronary calcium were not consistent among participant subgroups. Further research is required to determine the association between circulating biomarkers, coronary and extracoronary calcium.

Comparing nanoparticles for drug delivery: The effect of physiological dispersion media on nanoparticle properties.

Delivering therapeutics to disease sites is a challenge facing modern medicine. Nanoparticle delivery systems are of considerable interest to overcome this challenge, but these systems suffer from poor clinical translation. It is believed this is, in part, due to incomplete understanding of nanoparticle physico-chemical properties in vivo. To understand how nanoparticle properties could change following intravenous delivery, Au, Ag, Fe2O3, TiO2, and ZnO nanoparticles of 5, 20, and 50 nm were characterised in water and physiological fluids. The effects of the dispersion medium, concentration, and incubation time on size, dispersion, and zeta potential were measured. Properties varied significantly depending on material type, size, and concentration over 24 h. Gold and silver nanoparticles were generally the most stable. Meanwhile, 20 nm nanoparticles appeared to be the least stable size, across materials. These results could have important implications for selecting nanoparticles for drug delivery that will elicit the desired physiological response.

Drug delivery across the blood-brain barrier: recent advances in the use of nanocarriers.

The blood-brain barrier (BBB) has a significant contribution to homeostasis and protection of the CNS. However, it also limits the crossing of therapeutics and thereby complicates the treatment of CNS disorders. To overcome this limitation, the use of nanocarriers for drug delivery across the BBB has recently been exploited. Nanocarriers can utilize different physiological mechanisms for drug delivery across the BBB and can be modified to achieve the desired kinetics and efficacy. Consequentially, several nanocarriers have been reported to act as functional nanomedicines in preclinical studies using animal models for human diseases. Given the rapid development of novel nanocarriers, this review provides a comprehensive insight into the most recent advancements made in nanocarrier-based drug delivery to the CNS, such as the development of multifunctional nanomedicines and theranostics.

A blood biomarker and clinical correlation cohort study protocol to diagnose sports-related concussion and monitor recovery in elite rugby.

INTRODUCTION: In professional rugby, sports-related concussion (SRC) remains the most frequent time loss injury. Therefore, accurately diagnosing SRC and monitoring player recovery, through a multi-modal assessment process, is critical to SRC management. In this protocol study, we aim to assess SRC over multiple time points post-injury to determine the value of multi-modal assessments to monitor player recovery. This is of significance to minimise premature return-to-play and, ultimately, to reduce the long-term effects associated with SRC. The study will also establish the logistics of implementing such a study in a professional setting to monitor a player's SRC recovery. METHODS AND ANALYSIS: All players from the participating professional rugby club within the Irish Rugby Football Union are invited to participate in the current study. Player assessment includes head injury assessment (HIA), neuropsychometric assessment (ImPACT), targeted biomarker analysis and untargeted biomarker analysis. Baseline HIA, ImPACT, and blood draws are performed prior to the start of playing season. During the baseline tests, player's complete consent forms and an SRC history questionnaire. Subsequently, any participant that enters the HIA process over the playing season due to a suspected SRC will be clinically assessed (HIA and ImPACT) and their blood will be drawn within 3 days of injury, 6 days post-injury, and 13 days post-injury. ETHICS AND DISSEMINATION: Ethical approval was attained from the Science and Engineering Research Ethics Committee, University of Limerick (Approval Code: 2018_06_11_S&E). On completion of the study, further manuscripts will be published to present the results of the tests and their ability to measure player recovery from SRC. TRIAL REGISTRATION NUMBER: NCT04485494.

Standardization of research methods employed in assessing the interaction between metallic-based nanoparticles and the blood-brain barrier: Present and future perspectives.

Treating diseases of the central nervous system (CNS) is complicated by the presence of the blood-brain barrier (BBB), a semipermeable boundary layer protecting the CNS from toxins and homeostatic disruptions. However, this layer also excludes almost 100% of therapeutics, impeding the treatment of CNS diseases. The advent of nanoparticles, in particular metallic-based nanoparticles, presents the potential to overcome this barrier and transport drugs into the CNS. Recent interest in metallic-based nanoparticles has generated an immense array of information pertaining to nanoparticles of different materials, sizes, morphologies, and surface properties. Nanoparticles with different physico-chemical properties lead to distinct nanoparticle-host interactions; yet, comprehensive characterization is often not completed. Similarly, in vivo testing has involved a mixed evaluation of parameters, including: BBB permeability, integrity, biodistribution, and toxicity. The methods applied to assess these parameters are inconsistent; this complicates the comparison of different nanoparticle-host system responses. A systematic review was conducted to investigate the methods by which metallic-based nanoparticles are characterized and assessed in vivo. The introduction of a standardized approach to nanoparticle characterization and in vivo testing is crucial if research is to transition to a clinical setting. The approach suggested, herein, is based on equipment and techniques that are accessible and informative to facilitate the routine incorporation of this standardized, informative approach into different research settings. Thorough characterization could lead to improved interpretation of in vivo responses, which could clarify nanoparticle properties that result in favorable in vivo outcomes whilst exposing nanoparticle-specific weaknesses. Only then will researchers successfully identify nanoparticles capable of delivering life-saving therapeutics across the blood-brain barrier.

Regional mechanical and biochemical properties of the porcine cortical meninges.

The meninges are pivotal in protecting the brain against traumatic brain injury (TBI), an ongoing issue in most mainstream sports. Improved understanding of TBI biomechanics and pathophysiology is desirable to improve preventative measures, such as protective helmets, and advance our TBI diagnostic/prognostic capabilities. This study mechanically characterised the porcine meninges by performing uniaxial tensile testing on the dura mater (DM) tissue adjacent to the frontal, parietal, temporal, and occipital lobes of the cerebellum and superior sagittal sinus region of the DM. Mechanical characterisation revealed a significantly higher elastic modulus for the superior sagittal sinus region when compared to other regions in the DM. The superior sagittal sinus and parietal regions of the DM also displayed local mechanical anisotropy. Further, fatigue was noted in the DM following ten preconditioning cycles, which could have important implications in the context of repetitive TBI. To further understand differences in regional mechanical properties, regional variations in protein content (collagen I, collagen III, fibronectin and elastin) were examined by immunoblot analysis. The superior sagittal sinus was found to have significantly higher collagen I, elastin, and fibronectin content. The frontal region was also identified to have significantly higher collagen I and fibronectin content while the temporal region had increased elastin and fibronectin content. Regional differences in the mechanical and biochemical properties along with regional tissue thickness differences within the DM reveal that the tissue is a non-homogeneous structure. In particular, the potentially influential role of the superior sagittal sinus in TBI biomechanics warrants further investigation. STATEMENT OF SIGNIFICANCE: This study addresses the lack of regional mechanical analysis of the cortical meninges, particularly the dura mater (DM), with accompanying biochemical analysis. To mechanically characterise the stiffness of the DM by region, uniaxial tensile testing was carried out on the DM tissue adjacent to the frontal, parietal, temporal and occipital lobes along with the DM tissue associated with the superior sagittal sinus. To the best of the authors' knowledge, the work presented here identifies, for the first time, the heterogeneous nature of the DM's mechanical stiffness by region. In particular, this study identifies the significant difference in the stiffness of the DM tissue associated with the superior sagittal sinus when compared to the other DM regions. Constitutive modelling was carried out on the regional mechanical testing data for implementation in Finite Element models with improved biofidelity. This work also presents the first biochemical analysis of the collagen I and III, elastin, and fibronectin content within DM tissue by region, providing useful insights into the accompanying macro-scale biomechanical data.