Advanced nanoscale delivery systems for mRNA-based vaccines.

The effectiveness of messenger RNA (mRNA) vaccines, especially those designed for COVID-19, relies heavily on sophisticated delivery systems that ensure efficient delivery of mRNA to target cells. A variety of nanoscale vaccine delivery systems (VDSs) have been explored for this purpose, including lipid nanoparticles (LNPs), liposomes, and polymeric nanoparticles made from biocompatible polymers such as poly(lactic-co-glycolic acid), as well as viral vectors and lipid-polymer hybrid complexes. Among these, LNPs are particularly notable for their efficiency in encapsulating and protecting mRNA. These nanoscale VDSs can be engineered to enhance stability and facilitate uptake by cells. The choice of delivery system depends on factors like the specific mRNA vaccine, target cell types, stability requirements, and desired immune response. In this review, we shed light on recent advances in delivery mechanisms for self-amplifying RNA (saRNA) vaccines, emphasizing groundbreaking studies on nanoscale delivery systems aimed at improving the efficacy and safety of mRNA/saRNA vaccines.

Recent advances in nanoscale targeted therapy of HER2-positive breast cancer.

Breast cancer is considered as the second major cause of death among women with a high mortality rate worldwide. The exceptionally fast rate of metastasis, the emergence of drug-resistant mechanisms, and the occurrence of inadvertent side effects by cytotoxic chemotherapies often make conventional chemotherapy and immunotherapy treatments ineffective. Similar to other solid tumours, breast cancer can develop unique cellular and molecular characteristics forming an atypical permissive tumour microenvironment (TME). Due to the unique features of TME, cancer cells can further proliferate and coadapt with the stromal cells and evade immunosurveillance. Breast cancer cells aberrantly abundantly express various pieces of molecular machinery (the so-called oncomarkers) in favour of their survival, progression, metastasis, and further invasion. Such overexpressed oncomarkers can be exploited in the detection and targeted therapy of cancer. Among breast cancer oncomarkers, epidermal growth factor receptors, particularly HER2, are considered as clinically valid molecular targets not only for the thorough diagnosis but also for the targeted therapy of the disease using different conventional and advanced nanoscale treatment modalities. This review aims to elaborate on the recent advances in terms of targeted therapy of HER2-positive breast cancer, and discuss various types of multifunctional nanomedicines/theranostics, and antibody-/aptamer-drug conjugates.

Impacts of oxidants and antioxidants on the emergence and progression of Alzheimer's disease.

The brain shows a high sensitivity to oxidative stress (OS). Thus, the maintenance and homeostasis of the brain, in particular neural cells, regarding the reduction-oxidation (redox) situation is crucial for the regular function of the central nervous systems (CNS). The imbalance between the reactive oxygen species (ROS) and the cellular mechanism(s) might lead to the emergence of OS, resulting in possible cell death and tissue damages, and initiating neurodegenerative disorders (NDDs). Characterized by the cytoplasmic growth of neurofibrillary tangles and extracellular ß-amyloid plaques, Alzheimer's disease (AD) is a complex NDD that causes dementia in adult life with severe manifestations. Nuclear factor erythroid 2-related factor 2 (NRF2) is a key transcription factor that regulates the functional expression of OS-related genes and the functionality of endogenous antioxidants in response to ROS. In the case of oxidative damage, NRF2 is transferred to the nucleus and attached to the antioxidant response element (ARE), which can subsequently enhance the functional expression of the cell-protecting genes. In this review, we impart on the key mechanisms engaged in the generation of active and reactive species of endogenous and exogenous oxidants and discuss the antioxidants as the defense system of neural cells regarding the NRF2-ARE signaling path in the CNS.

Cell proliferation and anti-oxidant effects of oxytocin and oxytocin receptors: role of extracellular signal-regulating kinase in astrocyte-like cells.

OBJECTIVES: Oxytocin (OXT) participates in various physiological functions ranging from reproduction to social and non-social behaviors. Recent studies indicate that OXT affects cell growth and metabolism. Here we characterized the growth stimulating and antioxidant actions of OXT and of OXT receptors (OXTR) in a glial cell-line (U-87MG). METHODS: We developed an OXTR-knockdown cell-line (U-87MG KD) to establish the receptor specificity of OXT's actions, and the impact of lacking OXTR on growth and survival in glial cells. The role Extracellular-Signal Regulated Kinases (ERK1/2) on glial cell protection against consequences of oxidative stress, and cell proliferation was investigated. RESULTS: In U-87MG cells, OXT stimulated cell proliferation and increased ERK1/2 phosphorylation. The specific ERK1/2 inhibitor, PD098059, produced marked inhibition of cell proliferation, and antagonized the stimulating effect of OXT on ERK1/2 phosphorylation and on cell proliferation. Slower growth rates and lower levels of phosphorylated ERK1/2 were observed in OXTR-knockdown cells and in U-87MG cells treated with an OXTR antagonist (L-371,257). In addition to increasing cell proliferation, OXT significantly blunted the rise in reactive oxygen species induced by H2O2, and antagonized the reductions in cell viability induced by H2O2 and camptothecin. The cell protective and antioxidant actions of OXT in U-87MG cells were not observed in the OXTR-knockdown cells. CONCLUSION: OXT stimulates the growth of astrocyte-like cells acting on OXTR via ERK1/2 phosphorylation. The protection against apoptosis and the antioxidant capacity of OXT may contribute to the observed increase in cell proliferation. Oxytocin and OXTR appear to be fundamental for cell growth and viability of glial cells.

Nutritional interventions for autism spectrum disorder.

Autism spectrum disorder (ASD) is an increasingly prevalent neurodevelopmental disorder with considerable clinical heterogeneity. With no cure for the disorder, treatments commonly center around speech and behavioral therapies to improve the characteristic social, behavioral, and communicative symptoms of ASD. Gastrointestinal disturbances are commonly encountered comorbidities that are thought to be not only another symptom of ASD but to also play an active role in modulating the expression of social and behavioral symptoms. Therefore, nutritional interventions are used by a majority of those with ASD both with and without clinical supervision to alleviate gastrointestinal and behavioral symptoms. Despite a considerable interest in dietary interventions, no consensus exists regarding optimal nutritional therapy. Thus, patients and physicians are left to choose from a myriad of dietary protocols. This review, summarizes the state of the current clinical and experimental literature on nutritional interventions for ASD, including gluten-free and casein-free, ketogenic, and specific carbohydrate diets, as well as probiotics, polyunsaturated fatty acids, and dietary supplements (vitamins A, C, B6, and B12; magnesium and folate).

Clinical study of effectiveness and safety of CELcomplex® containing Cucurbita Pepo Seed extract and Flax and Casuarina on stress urinary incontinence in women.

AIM: The safety and effectiveness of a preparation containing a mix of Cucurbita Pepo Seed extract, Equisetum arvense and Linum usitatissimum - Flax A (CELcomplex®) on stress urinary incontinence (SUI) was evaluated in female patients recruited from 20 urological and gynaecological outpatient clinics in Slovakia. METHODS: A total of 86 women aged from 32 to 88 with SUI (grade 1 = 44, grade 2 = 42) were enrolled in the study and followed-up for six weeks (point 1) and twelve weeks (point 2). The primary outcome of the study was evaluated by changes in day-time and nocturnal urinary frequency (bathroom visits) and urinary incontinence episodes (leaks). Also, adverse events were quantified as well as the self-perceived effectiveness of the treatment. Research Ethics Board approval was obtained for this study. RESULTS: After 12 weeks of treatment there was a 30% (grade 1 SUI, p < 0.01), and 35% (grade 2 SUI, p < 0.01) improvement in urinary incontinence episodes, a 40% (grade 1 SUI, p < 0.01) and 26% (grade 2 SUI, p < 0.01) improvement in day-time urination frequency and 64% (grade 1 SUI, p < 0.01) and 54% (grade 2 SUI, p < 0.01) improvement in nocturnal urinary frequency. Reported side effects were: headache (3.5%), flatulence (4.1%) and gastrointestinal discomfort (3%). A total of 89.4 % of women in the study reported no side effects from this therapy and 97% acknowledged improvement of symptoms. CONCLUSION: This clinical study demonstrated that a 12 week treatment with a mix of Cucurbita Pepo Seed extract, Equisetum arvense and Linum usitatissimum - Flax A (CELcomplex®) is highly effective on stress urinary incontinence (SUI) with minimum adverse events. Further studies may be needed in order to determine the effectiveness and efficacy of this phytotherapy in other populations.

Are Molecules Involved in Neuritogenesis and Axon Guidance Related to Autism Pathogenesis?

Autism spectrum disorder is a heterogeneous disease, and numerous alterations of gene expression come into play to attempt to explain potential molecular and pathophysiological causes. Abnormalities of brain development and connectivity associated with alterations in cytoskeletal rearrangement, neuritogenesis and elongation of axons and dendrites might represent or contribute to the structural basis of autism pathology. Slit/Robo signaling regulates cytoskeletal remodeling related to axonal and dendritic branching. Components of its signaling pathway (ABL and Cdc42) are suspected to be molecular bases of alterations of normal development. The present review describes the most important mechanisms underlying neuritogenesis, axon pathfinding and the role of GTPases in neurite outgrowth, with special emphasis on alterations associated with autism spectrum disorders. On the basis of analysis of publicly available microarray data, potential biomarkers of autism are discussed.

Upregulation of angiotensin II-AT1 receptors during statin withdrawal in vascular smooth muscle cells.

Acute discontinuation of statins induces vascular dysfunction and increases cardiovascular events. The mechanisms underlying these events are under investigation. We showed an increase in angiotensin II (AngII) signaling after acute statin withdrawal. We investigated whether AngII-AT1-receptor expression (AT1-R mRNA) and receptor protein (AT1-R) levels mediate increased AngII signaling. In rat aortic vascular smooth muscle cells (VSMC), simvastatin (0.3 to 3 microM for 24 hours) resulted in concentration-dependent inhibition of AngII-stimulated phosphorylation of extracellular-signal regulated kinase 1/2 ERK1/2 (-67 +/- 5% with 3 microM; P < 0.001) and decreased AT1-R mRNA (-34 +/- 8% with 3 microM; P < 0.01) and AT1-R protein (-32 +/- 6% with 3 microM; P < 0.01). Removal of simvastatin led to a rebound increase in mRNA-AT1-R (+39 +/- 2%, P < 0.01), AT1-R protein (+46 +/- 2%; P < 0.01), and AngII-mediated phosphorylation of ERK1/2 (+36 +/- 3%; P < 0.01). The increase in receptor expression was present at 1 hour and lasted for 4 hours, whereas increased AT1-R protein and AngII signaling started at 2 hours and lasted for nearly 2 hours. In summary, increased AngII signaling after statin withdrawal is most likely due to increases in AT1-R number due to increased transcription. The increase in AngII activity may contribute to the vascular dysfunction associated with statin withdrawal.

Effects of statin treatment and withdrawal on angiotensin II-induced phosphorylation of p38 MAPK and ERK1/2 in cultured vascular smooth muscle cells.

Abrupt discontinuation of 3-hydroxy-3-methylglutaryl-coenzyme-A-reductase inhibitors (statins) is associated with increased cardiovascular risk. To investigate the molecular mechanisms determining the increased cardiovascular risk after statin withdrawal, we studied the effects of statin treatment and withdrawal on angiotensin II (AII) actions in rat aortic vascular smooth muscle cells (VSMC) in culture. In VSMC, AII stimulated the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2), and of p38 mitogen-activated protein kinase (p38 MAPK), with an EC50% of 0.86 and 3 nM, respectively. Maximal stimulation was observed after 5-10 min of exposure to AII. Pretreatment with 1-3 microM simvastatin for 24h inhibited AII-mediated stimulation of ERK1/2 and p38 MAPK phosphorylation; without affecting the levels on non-phosphorylated MAPK. Washout of simvastatin produced a rebound increase above control levels of AII-mediated phosphorylation of ERK1/2 and p38 MAPK. As previously reported for other agonists, the rebound increase of AII effects was observed from 1 to 3h after statin withdrawal, and was lost at later times. The basal levels of phosphorylation and the amount of non-phosphorylated kinases were unaffected by statin withdrawal. Similar effects were observed with lovastatin. Our results suggest that statins modulate AII effects in VSMC, and that transient increases in AII effects mediated via the MAPK pathway may play a role in the vascular dysfunction associated with statin withdrawal.

CYP11B2-CYP11B1 haplotypes associated with decreased 11 beta-hydroxylase activity.

Reduced adrenal 11 beta-hydroxylation has been associated with an aldosterone synthase (CYP11B2) polymorphism. The 11 beta-hydroxylase gene (CYP11B1) lies close to CYP11B2. We hypothesize that a molecular variant in CYP11B2 is in linkage disequilibrium (LD) with a key quantitative trait in CYP11B1 determining this phenotype. Polymorphisms and inferred haplotypes at CYP11B loci were studied in two independent populations from Europe (n = 100) and South America (n = 99). The latter underwent detailed hormonal studies. LD was estimated by alternative Bayesian methods for inferring the extent of LD when haplotypes at different loci are inferred. Population differences in single nucleotide polymorphisms were modest, indicating the stability of both genes across populations. Using five of nine potentially informative loci at CYP11B sites with allele frequency greater than 0.1, two major contrasting haplotypes, CwtCG and TconvGTA, were found. In both populations the CwtCG haplotype accounted for 44% and the TconvGTA for 32% of subjects. Haplotype distribution did not differ between Europeans and South Americans (chi(2) = 2.81; P = 0.09). In vivo 11 beta-hydroxylase activity, estimated from urinary steroid profiling, was lower in subjects with an increased aldosterone to renin ratio or with the TconvGTA haplotype. These findings indicate that genotypes at the CYP11B locus are in strong LD and that identified haplotypes predict 11 beta-hydroxylase activity.

Alpha-adducin polymorphism, salt sensitivity, nitric oxide excretion, and cardiovascular risk factors in normotensive Hispanics.

BACKGROUND: Genetic and environmental factors determine the blood pressure (BP) response to changes in salt intake. Mutations in the alpha-adducin gene may be associated with hypertension and salt-sensitive hypertension. We investigated whether one alpha-adducin polymorphism, the Gly460Trp (G/T) variant, was associated with salt sensitivity, nitric oxide (NO) production; and cardiovascular risk factors in healthy adult normotensive Venezuelans. METHODS AND RESULTS: Subjects (n = 126) were screened for salt sensitivity. The alpha-Adducin polymorphism was tested in salt-sensitive (SS) and salt-resistant (SR) subjects. The G/T and G/G (wild gene) groups had similar BP levels. The G/T subjects had higher LDL-cholesterol (P =.01) and postload glucose AUC (P =.03) than G/G individuals. Genotype frequencies were not associated with BP or salt sensitivity (G/G, 38.1% SS and 61.9% SR vs G/T, 40.7% SS and 59.3% SR). Shifting from high salt to low salt diet produced comparable reductions in systolic BP and diastolic BP in G/T and G/G groups. The G/G and G/T groups excreted similar amounts of sodium on high and low salt diets. The SR subjects carrying the wild or the mutated gene showed no changes in NO metabolite excretion at different levels of salt intake. In SS subjects, the level of NO metabolite excretion was highly dependent on salt intake. A combination of SS and 460Trp mutation enhanced the sodium-dependent modulation of NO production. CONCLUSIONS: In normotensive Venezuelans, the alpha-adducin G/T polymorphism was not associated with BP, salt sensitivity, or with sodium excretion during sodium loading or restriction. G/T was associated with increased LDL-cholesterol and postload glucose levels. In SS, G/T was associated with greater salt-dependent modulation of NO excretion. However, this larger increase in NO excretion was not associated with a larger decrease in BP.