Intranasal delivery of a Fas-blocking peptide attenuates Fas-mediated apoptosis in brain ischemia

Intranasal Delivery of Cell-Penetrating Therapeutic Peptide Enhances Brain Delivery, Reduces Inflammation, and Improves Neurologic Function in Moderate Traumatic Brain Injury

Following traumatic brain injury (TBI), secondary brain damage due to chronic inflammation is the most predominant cause of the delayed onset of mood and memory disorders. Currently no therapeutic approach is available to effectively mitigate secondary brain injury after TBI. One reason is the blood-brain barrier (BBB), which prevents the passage of most therapeutic agents into the brain. Peptides have been among the leading candidates for CNS therapy due to their low immunogenicity and toxicity, bioavailability, and ease of modification. In this study, we demonstrated that non-invasive intranasal (IN) administration of KAFAK, a cell penetrating anti-inflammatory peptide, traversed the BBB in a murine model of diffuse, moderate TBI. Notably, KAFAK treatment reduced the production of proinflammatory cytokines that contribute to secondary injury. Furthermore, behavioral tests showed improved or restored neurological, memory, and locomotor performance after TBI in KAFAK-treated mice. This study demonstrates KAFAK's ability to cross the blood-brain barrier, to lower proinflammatory cytokines in vivo, and to restore function after a moderate TBI.

Eye Drop with Fas-Blocking Peptide Attenuates Age-Related Macular Degeneration

Age-related macular degeneration (AMD), characterized by macular retinal degeneration, poses a significant health concern due to the lack of effective treatments for prevalent dry AMD. The progression of AMD is closely linked to reactive oxygen species and Fas signaling, emphasizing the need for targeted interventions. In this study, we utilized a NaIO3-induced retinal degeneration mouse model to assess the efficacy of Fas-blocking peptide (FBP). Intravitreal administration of FBP successfully suppressed Fas-mediated inflammation and apoptosis, effectively arresting AMD progression in mice. We developed a 6R-conjugated FBP (6R-FBP) for eye drop administration. 6R-FBP, administered as an eye drop, reached the retinal region, attenuating degeneration by modulating the expression of inflammatory cytokines and blocking Fas-mediated apoptosis in rodent and rabbit NaIO3-induced retinal degeneration models to address practical concerns. Intravitreal FBP and 6R-FBP eye drops effectively reduced retinal degeneration and improved retinal thickness in rodent and rabbit models. This study highlights the therapeutic potential of FBP, particularly 6R-FBP as an eye drop, in inhibiting Fas-mediated cell signaling and protecting against retinal cell death and inflammation in dry AMD. Future investigations should explore the translational prospects of this approach in primates with eye structures comparable to those of humans.

Cadmium neurotoxicity and therapeutic strategies

Cadmium (Cd) is a multitarget, carcinogenic, nonessential environmental pollutant. Due to its toxic effects at very low concentrations, lengthy biological half-life, and low excretion rate, exposure to Cd carries a concern. Prolonged exposure to Cd causes severe injury to the nervous system of both humans and animals. Nevertheless, the precise mechanisms responsible for the neurotoxic effects of Cd have yet to be fully elucidated. The accurate chemical mechanism potentially entails the destruction of metal-ion homeostasis, inducing oxidative stress, apoptosis, and autophagy. Here we review the evidence of the neurotoxic effects of Cd and corresponding strategies to protect against Cd-induced central nervous system injury.

Intranasal Delivery of Anti-Apoptotic siRNA Complexed with Fas-Signaling Blocking Peptides Attenuates Cellular Apoptosis in Brain Ischemia

Ischemic stroke-induced neuronal cell death leads to the permanent impairment of brain function. The Fas-mediating extrinsic apoptosis pathway and the cytochrome c-mediating intrinsic apoptosis pathway are two major molecular mechanisms contributing to neuronal injury in ischemic stroke. In this study, we employed a Fas-blocking peptide (FBP) coupled with a positively charged nona-arginine peptide (9R) to form a complex with negatively charged siRNA targeting Bax (FBP9R/siBax). This complex is specifically designed to deliver siRNA to Fas-expressing ischemic brain cells. This complex enables the targeted inhibition of Fas-mediating extrinsic apoptosis pathways and cytochrome c-mediating intrinsic apoptosis pathways. Specifically, the FBP targets the Fas/Fas ligand signaling, while siBax targets Bax involved in mitochondria disruption in the intrinsic pathway. The FBP9R carrier system enables the delivery of functional siRNA to hypoxic cells expressing the Fas receptor on their surface-a finding validated through qPCR and confocal microscopy analyses. Through intranasal (IN) administration of FBP9R/siCy5 to middle cerebral artery occlusion (MCAO) ischemic rat models, brain imaging revealed the complex specifically localized to the Fas-expressing infarcted region but did not localize in the non-infarcted region of the brain. A single IN administration of FBP9R/siBax demonstrated a significant reduction in neuronal cell death by effectively inhibiting Fas signaling and preventing the release of cytochrome c. The targeted delivery of FBP9R/siBax represents a promising alternative strategy for the treatment of brain ischemia.

Systemic Treatment with Fas-Blocking Peptide Attenuates Apoptosis in Brain Ischemia

Apoptosis plays a crucial role in neuronal injury, with substantial evidence implicating Fas-mediated cell death as a key factor in ischemic strokes. To address this, inhibition of Fas-signaling has emerged as a promising strategy in preventing neuronal cell death and alleviating brain ischemia. However, the challenge of overcoming the blood-brain barrier (BBB) hampers the effective delivery of therapeutic drugs to the central nervous system (CNS). In this study, we employed a 30 amino acid-long leptin peptide to facilitate BBB penetration. By conjugating the leptin peptide with a Fas-blocking peptide (FBP) using polyethylene glycol (PEG), we achieved specific accumulation in the Fas-expressing infarction region of the brain following systemic administration. Notably, administration in leptin receptor-deficient db/db mice demonstrated that leptin facilitated the delivery of FBP peptide. We found that the systemic administration of leptin-PEG-FBP effectively inhibited Fas-mediated apoptosis in the ischemic region, resulting in a significant reduction of neuronal cell death, decreased infarct volumes, and accelerated recovery. Importantly, neither leptin nor PEG-FBP influenced apoptotic signaling in brain ischemia. Here, we demonstrate that the systemic delivery of leptin-PEG-FBP presents a promising and viable strategy for treating cerebral ischemic stroke. Our approach not only highlights the therapeutic potential but also emphasizes the importance of overcoming BBB challenges to advance treatments for neurological disorders.

Antisense-oligonucleotide co-micelles with tumor targeting peptides elicit therapeutic effects by inhibiting microRNA-21 in the glioblastoma animal models

INTRODUCTION

miRNA-21 (miR-21) is highly expressed in glioblastoma, facilitating tumor growth by blocking the expression of apoptosis-related genes. Therefore, an antisense microRNA oligonucleotide (AMO) against miR-21 was suggested as a therapeutic nucleic acid for glioblastoma.

OBJECTIVES

AMO21 co-micelles were developed with tumor-targeting T7 peptides as an AMO21 delivery system by intranasal administration.

METHODS

Cholesterol-conjugated AMO21 (AMO21c) was mixed with cholesterol-conjugated T7 peptides (T7c) to produce tumor-targeted co-micelles. Physical characterization was performed by dynamic light scattering, gel retardation assay, scanning electron microscope and heparin competition assay. In vitro transfection efficiency to C6 glioblastoma cells was measured by flow cytometry. The AMO21c/T7c co-micelles were administered by intranasal instillation into the brain of intracranial glioblastoma rat models. Scrambled T7 (scrT7) and scrambled AMO21c (scrAMO21c) were used as a negative control. The therapeutic effects of the AMO21c/T7c co-micelles were evaluated by real time RT-PCR, immunohistochemistry, TUNEL assay, and Nissl staining.

RESULTS

The formation of the AMO21c/T7c co-micelles was confirmed in gel retardation and heparin competition assays. The highest delivery efficiency in vitro was achieved at a 1:10 wt ratio of AMO21c/T7c. The AMO21c/T7c co-micelles had higher delivery efficiency into C6 glioblastoma cells than naked AMO21c or AMO21c/lipofectamine complexes. After intranasal administration into the intracranial glioblastoma models, the delivery efficiency of the co-micelles into the brain was also higher than those of naked AMO21c and AMO21c/scrambled T7c. Thanks to their enhanced delivery efficiency, the AMO21c/T7c co-micelles downregulated miR-21, inducing the production of the pro-apoptotic phosphatase and tensin homolog (PTEN) and programmed cell death 4 (PDCD4) proteins in the tumor tissues. The tumor size was reduced by the AMO21c/T7c co-micelles more effectively than naked AMO21c, AMO21c/lipofectamine, or scrAMO21c/T7c treatment.

CONCLUSION

The results suggest that the co-micelles of AMO21c and T7c may be an efficient delivery system into a brain tumor through intranasal administration.

Apoptotic cell death in disease-Current understanding of the NCCD 2023

Apoptosis is a form of regulated cell death (RCD) that involves proteases of the caspase family. Pharmacological and genetic strategies that experimentally inhibit or delay apoptosis in mammalian systems have elucidated the key contribution of this process not only to (post-)embryonic development and adult tissue homeostasis, but also to the etiology of multiple human disorders. Consistent with this notion, while defects in the molecular machinery for apoptotic cell death impair organismal development and promote oncogenesis, the unwarranted activation of apoptosis promotes cell loss and tissue damage in the context of various neurological, cardiovascular, renal, hepatic, infectious, neoplastic and inflammatory conditions. Here, the Nomenclature Committee on Cell Death (NCCD) gathered to critically summarize an abundant pre-clinical literature mechanistically linking the core apoptotic apparatus to organismal homeostasis in the context of disease.

Chemical Knockdown of Phosphorylated p38 Mitogen-Activated Protein Kinase (MAPK) as a Novel Approach for the Treatment of Alzheimer's Disease

Targeted protein degradation (TPD) provides unique advantages over gene knockdown in that it can induce selective degradation of disease-associated proteins attributed to pathological mutations or aberrant post-translational modifications (PTMs). Herein, we report a protein degrader, PRZ-18002, that selectively binds to an active form of p38 MAPK. PRZ-18002 induces degradation of phosphorylated p38 MAPK (p-p38) and a phosphomimetic mutant of p38 MAPK in a proteasome-dependent manner. Given that the activation of p38 MAPK plays pivotal roles in the pathophysiology of Alzheimer's disease (AD), selective degradation of p-p38 may provide an attractive therapeutic option for the treatment of AD. In the 5xFAD transgenic mice model of AD, intranasal treatment of PRZ-18002 reduces p-p38 levels and alleviates microglia activation and amyloid beta (Aβ) deposition, leading to subsequent improvement of spatial learning and memory. Collectively, our findings suggest that PRZ-18002 ameliorates AD pathophysiology via selective degradation of p-p38, highlighting a novel therapeutic TPD modality that targets a specific PTM to induce selective degradation of neurodegenerative disease-associated protein.

Elevated soluble fas blood concentrations in patients dying from spontaneous intracerebral hemorrhage

BACKGROUND

Several studies of spontaneous intracerebral hemorrhage (SICH) patients have shown apoptotic changes in brain samples after hematoma evacuation. However, there have been no data on the association between blood concentrations of soluble fas (sFas) (the main surface death receptor of the extrinsic apoptosis pathway) and the prognosis of spontaneous intracranial hypotension (SIH) patients.

AIM

To determine whether there is an association between blood sFas concentrations and SICH patient mortality.

METHODS

We included patients with severe and supratentorial SIH. Severe was defined as having Glasgow Coma Scale < 9. We determined serum sFas concentrations at the time of severe SICH diagnosis.

RESULTS

We found that non-surviving patients (n = 36) compared to surviving patients (n = 39) had higher ICH score (P = 0.001), higher midline shift (P = 0.004), higher serum sFas concentrations (P < 0.001), and lower rate of early hematoma evacuation (P = 0.04). Multiple logistic regression analysis showed an association between serum sFas concentrations and 30-d mortality (odds ratio = 1.070; 95% confidence interval = 1.014-1.129; P = 0.01) controlling for ICH score, midline shift, and early hematoma evacuation.

CONCLUSION

The association of blood sFas concentrations and SICH patient mortality is a novel finding in our study.

Very early environmental enrichment protects against apoptosis and improves functional recovery from hypoxic-ischemic brain injury

Appropriate rehabilitation of stroke patients at a very early phase results in favorable outcomes. However, the optimal strategy for very early rehabilitation is at present unclear due to the limited knowledge on the effects of very early initiation of rehabilitation based on voluntary exercise (VE). Environmental enrichment (EE) is a therapeutic paradigm for laboratory animals that involves complex combinations of physical, cognitive, and social stimuli, as well as VE. Few studies delineated the effect of EE on apoptosis in very early stroke in an experimental model. Although a minimal benefit of early rehabilitation in stroke models has been claimed in previous studies, these were based on a forced exercise paradigm. The aim of this study is to determine whether very early exposure to EE can effectively regulate Fas/FasL-mediated apoptosis following hypoxic-ischemic (HI) brain injury and improve neurobehavioral function. C57Bl/6 mice were housed for 2 weeks in either cages with EE or standard cages (SC) 3 h or 72 h after HI brain injury. Very early exposure to EE was associated with greater improvement in motor function and cognitive ability, reduced volume of the infarcted area, decreased mitochondria-mediated apoptosis, and decreased oxidative stress. Very early exposure to EE significantly downregulated Fas/FasL-mediated apoptosis, decreased expression of Fas, Fas-associated death domain, cleaved caspase-8/caspase-8, cleaved caspase-3/caspase-3, as well as Bax and Bcl-2, in the cerebral cortex and the hippocampus. Delayed exposure to EE, on the other hand, failed to inhibit the extrinsic pathway of apoptosis. This study demonstrates that very early exposure to EE is a potentially useful therapeutic translation for stroke rehabilitation through effective inhibition of the extrinsic and intrinsic apoptotic pathways.

Blood soluble Fas concentrations and ischemic stroke patient mortality

BACKGROUND

Fas is a major receptor for cell death by apoptosis. Higher blood concentrations of soluble Fas (sFas) have been reported in patients with ischemic stroke compared to control subjects. The aim of this study was to explore the existence or not of an association between blood sFas concentrations and mortality in patients with ischemic stroke.

METHODS

This study included patients admitted to Intensive Care Units with severe and malignant middle cerebral artery infarction (MCAI), defined as acute infarction, in more than 50% of this territory on computed tomography and less than 9 points on the Glasgow Coma Scale (GCS). Serum sFas levels were determined at the time of diagnosis of MMCAI.

RESULTS

Non-surviving severe MMCAI patients (n = 27) showed lower platelet count (p = 0.004), higher serum sFas (p < 0.001), and lower GCS (p = 0.001) compared to surviving patients (n = 27). Multiple logistic regression found an association of serum sFas levels and mortality at 30 days (OR = 1.015; 95% CI = 1.002-1.027; p = 0.02) after control for CGS and platelet count.

CONCLUSIONS

The main novelty of our study was the existence of an association between high blood sFas concentrations and mortality in patients with ischemic stroke.

High blood Fas concentrations in non-survivor patients with traumatic brain injury

Fas is one of the main death receptors of the extrinsic pathway of apoptosis. A study has reported higher Fas expression in brain samples of non-surviving TBI patients than in survivors. The objective of our current study was to determine whether there is an association between Fas concentrations in blood and mortality of isolated TBI patients. Patients with severe TBI [< 9 points in Glasgow Coma Scale (GCS)] and isolated TBI (< 10 non-cranial aspects points on the Injury Severity Score) were included from 5 Intensive Care Units. We measured serum Fas concentrations on the day of TBI. Non-surviving (n = 23) compared to surviving patients (n = 57) had higher age (p = 0.01), lower GCS (p = 0.001), higher APACHE-II score (p < 0.001), higher ICP (p = 0.01), higher CT findings with high risk of death (p = 0.02) and higher serum Fas concentrations (p < 0.001). We found in regression analyses an association between serum Fas levels and mortality of TBI patients after controlling for CT findings, age and CGS (OR = 1.006; 95% CI 1.001-1.011; p = 0.02), and after controlling for CT findings, ICP and APACHE-II (OR = 1.007; 95% CI 1.001-1.012; p = 0.02). Thus, the most interesting and novel finding in this study is the association between high blood Fas concentrations and mortality in TBI patients.

Mortality prediction of patients with spontaneous intracerebral hemorrhage by serum soluble Fas ligand concentrations

BACKGROUND

A study of patients with spontaneous intracerebral hemorrhage (SIH) found a higher content of Fas ligand in the perihematomic brain area compared to healthy brain areas. The objective of this study was to analyze whether blood soluble Fas ligand (sFasL) concentrations could be used to estimate the prognosis of SIH patients.

METHODS

Observational and prospective study performed in five Spanish Intensive Care Units. Patients with severe supratentorial SIH, defined as Glasgow Coma Scale (GCS) <9, were included. Serum sFasL levels were determined at the time of diagnosis of severe SIH. Mortality at 30 days was the end-point study.

RESULTS

Surviving SIH patients (n = 41) compared to nonsurvivors (n = 38) showed lower serum sFasL levels (p < 0.001). The area under curve of mortality prediction for serum sFasL levels was 0.79 (95% CI = 0.70-0.89; p < 0.001). Multiple logistic regression analysis found an association of serum sFasL concentrations with 30-day mortality (ORo = 1,034; 95% CI = 1,010-1,058; p = 0,006) after controlling for midline shift, early hematoma evacuation, and intracerebral hemorrhage score.

CONCLUSIONS

The capability of serum sFasL to predict SIH patient mortality is the main novel finding of our study.

ABBREVIATIONS

APACHE II: Acute Physiology and Chronic Health Evaluation; aPTT: activated partial thromboplastin time; FIO₂: fraction of inspired oxygen; GCS: Glasgow Coma Scale; ICU: Intensive Care Unit; INR: international normalized ratio; PaO₂: pressure of arterial oxygen.

Translocator Protein Regulate Polarization Phenotype Transformation of Microglia after Cerebral Ischemia-reperfusion Injury

Microglia cells are activated after cerebral ischemia-reperfusion injury (CIRI), playing a dual role in aggravating the injury or promoting tissue repair by polarization. Translocator protein (TSPO) is a biomarker of neuroinflammation or microglia activation. Its expression is significantly increased while brain injury and neuroinflammation occur. However, the relationship between TSPO and microglia polarization in CIRI is still not clear. In the present study, the middle cerebral artery occlusion (MCAO) methods in rats were used to simulate CIRI. We found that the expressions of M1 markers (CD86, IL-1β, and TNF-α) and M2 markers (CD206, IL-10, and TGF-β) were significantly increased. Moreover, the injection of TSPO ligand, PK11195, inhibited the increase of M1 polarization markers but promoted the expressions of M2 polarization markers, which significantly ameliorated the neurological damage after MCAO in rats. In vitro studies showed that shRNA-mediated TSPO knock-down promoted M1 polarization but inhibited M2 polarization, accompanied by a significant decrease in cell viability. On the contrary, overexpression of TSPO inhibited M1 polarization, promoted M2 polarization, and significantly improved cell viability. In summary, TSPO plays a neuroprotective role in CIRI by inhibiting M1 polarization and promoting M2 polarization, which suggests that TSPO may have the potential to serve as a therapeutic target for stroke.

Intranasal delivery of self-assembled nanoparticles of therapeutic peptides and antagomirs elicits anti-tumor effects in an intracranial glioblastoma model

MicroRNA-21 (miR-21) is involved in the progression of glioblastoma through inhibition of pro-apoptotic genes. Antisense RNA against miR-21 (antagomir-21) has been developed as a potential therapeutic reagent for the treatment of glioblastoma. The receptor for advanced glycation end-products (RAGE) is also involved in the progression of glioblastoma through induction of angiogenic factors. Therefore, RAGE-antagonist peptide (RAP) is proposed to be an anti-tumor reagent. In this study, self-assembled nanoparticles were produced solely with therapeutic agents, antagomir-21 and RAP, with no additional carrier. The therapeutic effects of the nanoparticles by intranasal delivery were evaluated in intracranial glioblastoma animal models. First, physical characterizations such as size/zeta-potential study, scanning electron microscopy, and gel retardation assays showed that antagomir-21 and RAP formed stable nanoparticles without any additional reagents. The ratio between antagomir-21 and RAP was optimized by an in vitro cellular uptake study. The antagomir-21/RAP nanoparticles were administrated intranasally in the intracranial glioblastoma animal models to bypass the blood-brain-barrier. As a result, the nanoparticles reduced the miR-21 levels in tumors. Inhibition of miR-21 by the nanoparticles induced the expression of pro-apoptotic genes, such as PTEN and PDCD4, which enhanced tumor cell apoptosis. In addition, the expression of RAGE was suppressed by the nanoparticles, resulting in decreased levels of vascular endothelial growth factor in the tumor. The reduction of CD31-positive endothelial cells confirmed the anti-angiogenic effects of the nanoparticles. The results indicate that the intranasal delivery of the self-assembled nanoparticles of antagomir-21 and RAP is an efficient treatment of glioblastoma.

Hypoxia-specific anti-RAGE exosomes for nose-to-brain delivery of anti-miR-181a oligonucleotide in an ischemic stroke model

Ischemic stroke is caused by a reduction in blood flow to the brain due to narrowed cerebral arteries. Thrombolytic agents have been used to induce reperfusion of occluded cerebral arteries. However, brain damage continues to progress after reperfusion and induces ischemia-reperfusion (I/R) injury. The receptor for advanced glycation end-products (RAGE) is overexpressed in hypoxic cells of the ischemic brain. In this study, an exosome linked to RAGE-binding-peptide (RBP-Exo) was developed as a hypoxia-specific carrier for nose-to-brain delivery of anti-microRNA oligonucleotide (AMO). The RBP-Exos were less than 50 nm in size and had negative surface charge. In vitro studies showed that RBP-Exos delivered AMO181a to Neuro2A cells more efficiently than unmodified exosomes (Unmod-Exos). In addition, RAGE was downregulated by RBP-Exos, suggesting that the RBP moiety of the RBP-Exos reduced the RAGE-mediated signal pathway. MicroRNA-181a (miR-181a) is one of the upregulated miRNAs in the ischemic brain and its downregulation can reduce the damage to the ischemic brain. Cholesterol-modified AMO181a (AMO181a-chol) was loaded onto the RBP-Exo by hydrophobic interaction. The AMO181a-chol-loaded RBP-Exo (RBP-Exo/AMO181a-chol) was administered intranasally to a rat middle cerebral artery occlusion (MCAO) model. MiR-181a was knocked down and Bcl-2 was upregulated by intranasal delivery of RBP-Exo/AMO181a-chol. In addition, tumor necrosis factor-α (TNF-α) expression and apoptosis were reduced by RBP-Exo/AMO181a-chol. As a result, RBP-Exo/AMO181a-chol significantly suppressed infarct size compared with the controls. In conclusion, RBP-Exo was a hypoxia-specific carrier for nose-to-brain delivery of AMO181a-chol in an ischemic stroke model. Furthermore, the combined effects of RBP and AMO181a-chol exerted neuroprotective effects in the ischemic brain.

Cerebral ischemic stroke and different approaches for treatment of stroke

Background

Cerebral ischemia can be considered a lethal disease as it is a leading cause of death worldwide with no prompt line of treatment. The factors which make this disease more fatal are failure of drugs while crossing BBB, very low availability of the drug in the brain, inefficiency of drug molecule in the clinical studies, limited availability of clinical data, lack of awareness about this disease, and many more.

Main body

This review focuses on reasons and mechanisms of stroke, classification of brain ischemia; it also reveals the current scenario of stroke in India. Very few drugs are effective for the treatment of stroke. This compilation furnishes conventional and recent treatments of stroke along with their hurdles like the gap between preclinical and clinical studies. This review also suggests effective routes of administration of drugs for the treatment of brain ischemia specifically nose-to-brain route and effectiveness of different dosage forms precisely nanoformulations, as the most effective dosage form.

Conclusion

By following different guidelines and treatments, the risk of brain ischemia can be minimized as well as some advanced techniques for the treatment of this disease proving their efficiency. One of the important aspects in the success of the treatment for this disease is the route of administration of the drug. Among all routes, intranasal drug delivery presents a potential approach and is supposed to be the next-generation therapy for brain disorders. The nose-to-brain route is very effective, and it shows some promising results in case of stroke treatment. The strategy is still under investigation despite various successful lab-scale studies; there are numerous challenges to reach the product in the market. Research is going on to get a better understanding of this strategy. We believe that detailed studies to resolve pitfalls will lead to the successful development of an intranasal formulation for the management of ischemic brain injury such as stroke.

Induction of mitochondrial apoptosis pathway mediated through caspase-8 and c-Jun N-terminal kinase by cadmium-activated Fas in rat cortical neurons

Cadmium (Cd) is a toxic metal and an environmental pollutant and can cause neurotoxicity by inducing apoptosis. Fas (CD95/Apo-1) is a cell-surface receptor that triggers apoptosis upon ligand binding, mediated through the mitochondrial apoptotic pathway. However, the role and regulatory mechanism of Fas in Cd-induced neuronal apoptosis remain understudied. Here, we demonstrate that activation of caspase-8 and the c-Jun N-terminal kinase (JNK) pathway are mechanisms underlying Cd-induced Fas-mediated activation of the mitochondrial apoptotic pathway in rat cerebral cortical neurons. In vitro, Cd induced apoptosis in primary cortical neurons by activating caspase-8, JNK, and the mitochondrial apoptotic pathway. Fas knockdown enhanced cell viability in the presence of Cd and inhibited apoptosis by blocking Cd-activated Fas, caspase-8, and JNK. Fas knockdown also inhibited the decrease of mitochondrial membrane potential, cleavage of caspase-9/3 and poly (ADP-ribose) polymerase 1, and impaired nuclear translocation of apoptosis-inducing factor and endonuclease G. In vivo, Fas knockdown alleviated Cd-induced neuronal injury and inhibited apoptosis, activation of caspase-8, JNK, and mitochondrial apoptotic pathways in rat cerebral cortical neurons. In summary, our results demonstrate that Cd-activated Fas relays apoptotic signals from the cell surface to the mitochondria via caspase-8 and JNK activation in rat cerebral cortical neurons, leading to aggravation of the neuronal injury.

Cellular and Molecular Mechanisms of R/S-Roscovitine and CDKs Related Inhibition under Both Focal and Global Cerebral Ischemia: A Focus on Neurovascular Unit and Immune Cells

Ischemic stroke is the second leading cause of death worldwide. Following ischemic stroke, Neurovascular Unit (NVU) inflammation and peripheral leucocytes infiltration are major contributors to the extension of brain lesions. For a long time restricted to neurons, the 10 past years have shown the emergence of an increasing number of studies focusing on the role of Cyclin-Dependent Kinases (CDKs) on the other cells of NVU, as well as on the leucocytes. The most widely used CDKs inhibitor, (R)-roscovitine, and its (S) isomer both decreased brain lesions in models of global and focal cerebral ischemia. We previously showed that (S)-roscovitine acted, at least, by modulating NVU response to ischemia. Interestingly, roscovitine was shown to decrease leucocytes-mediated inflammation in several inflammatory models. Specific inhibition of roscovitine majors target CDK 1, 2, 5, 7, and 9 showed that these CDKs played key roles in inflammatory processes of NVU cells and leucocytes after brain lesions, including ischemic stroke. The data summarized here support the investigation of roscovitine as a potential therapeutic agent for the treatment of ischemic stroke, and provide an overview of CDK 1, 2, 5, 7, and 9 functions in brain cells and leucocytes during cerebral ischemia.

High Serum Soluble Fas Ligand Levels in Non-survivor Traumatic Brain Injury Patients

PURPOSE

Soluble Fas Ligand (sFasL) is one of the main ligands that activates the apoptosis extrinsic pathway. Higher expression of FasL in brain samples and higher cerebrospinal fluid FasL concentrations in traumatic brain injury (TBI) patients than in controls have been found. However, the potential association between blood sFasL concentrations and TBI mortality has not been reported. Therefore, the objective of this study was to determine whether that association exists.

METHODS

We included patients with a severe isolated TBI, defined as < 9 points in Glasgow Coma Scale (GCS) and < 10 non-cranial aspects points in Injury Severity Score in this observational and prospective study performed in 5 Intensive Care Units. We measured serum sFasL concentrations on day 1 of TBI.

RESULTS

We found that 30-day survivor (n = 59) in comparison to non-survivor patients (n = 24) had higher GCS (p = 0.001), lower age (p = 0.004), lower APACHE-II score (p < 0.001), lower intracranial pressure (ICP) (p = 0.01), lower computer tomography (CT) findings of high risk of death (p = 0.02) and lower serum sFasL concentrations (p < 0.001). The area under the curve for mortality prediction by serum sFasL levels was of 75% (95% CI = 63%-87%; p < 0.001). In Kaplan-Meier analysis was found that patients with serum sFasL levels > 29.2 pg/mL had a higher mortality rate (Hazard ratio = 6.2; 95% CI = 2.6-14.8; p < 0.001). Multiple logistic regression analysis found an association between serum sFasL levels and mortality after controlling for GCS, age and CT findings (OR = 1.055; 95% CI = 1.018-1.094; p = 0.004), and after controlling for APACHE-II, ICP and CT findings (OR = 1.048; 95% CI = 1.017-1.080; p = 0.002).

CONCLUSIONS

The association between serum sFasL levels and 30-day mortality in TBI patients was the major novel finding of our study; however, future validation could be interesting to confirm those results.

Intranasal delivery of cancer-targeting doxorubicin-loaded PLGA nanoparticles arrests glioblastoma growth

Glioblastoma multiforme (GBM) is the most aggressive form of brain tumour and treatment is very challenging. Despite the recent advances in drug delivery systems, various approaches that allow sufficient deposition of anti-cancer drugs within the brain remain unsuccessful due to limited drug delivery throughout the brain. In this study, we utilised an intranasal (IN) approach to allow delivery of anti-cancer drug, encapsulated in PLGA nanoparticles (NPs). PLGA NPs were modified with the RGD ligand to enable A_vβ₃ expressing tumour-specific delivery. IN delivery of RGD-conjugated-doxorubicin (DOX)-loaded-PLGA-nanoparticles (RGD-DOX-NP) showed cancer-specific delivery of NP and inhibition of brain tumour growth compared to the free-DOX or non-modified DOX-NP in the C6-implanted GBM model. Further, IN treatment with RGD-DOX-NP induces apoptosis in the tumour region without affecting normal brain cells. Our study provides therapeutic evidence to treat GBM using a non-invasive IN approach, which may further be translated to other brain-associated diseases.

Development and Evaluation of in-situ Nasal Gel Formulations of Nanosized Transferosomal Sumatriptan: Design, Optimization, in vitro and in vivo Evaluation

Background

Sumatriptan succinate (SUT) is a potent drug used for relieving or ending migraine and cluster headaches. SUT bioavailability is low (15%) when it is taken orally owing to its gastric breakdown and bloodstream before reaching the target arteries.

Aim

The aim of the study was to enhance SUT bioavailability through developing an intranasal transferosomal mucoadhesive gel.

Methods

SUT-loaded nanotransferosomes were prepared by thin film hydration method and characterized for various parameters such as vesicle diameter, percent entrapment efficiency (%EE), in vitro release and ex vivo permeation studies. The in-situ gels were prepared using various ratios of poloxamer 407, poloxamer 188, and carrageenan and characterized for gelation temperature, mucoadhesive strength, and rheological properties.

Results

The prepared transferosomes exhibited percent entrapment efficiencies (%EE) of 40.41±3.02 to 77.47±2.85%, mean diameters of 97.25 to 245.01 nm, sustained drug release over 6 hours, and acceptable ex vivo permeation findings. The optimum formulae were incorporated into poloxamer 407 and poloxamer 188-based thermosensitive in-situ gel using carrageenan as a mucoadhesive polymer. Pharmacokinetic evaluation showed that the prepared in-situ gel of SUT-loaded nano-transferosomes gave enhanced bioavailability, 4.09-fold, as compared to oral drug solution.

Conclusion

Based on enhancing the bioavailability and sustaining the drug release, it can be concluded that the in-situ gel of SUT-loaded nano-transferosomes were developed as a promising non-invasive drug delivery system for treating migraine.

Intranasal delivery of M2 macrophage-derived soluble products reduces neuropsychological deficit in patients with cerebrovascular disease: a pilot study

Objective:

We assessed the safety and clinical effectiveness of intranasal therapy with M2 macrophage-derived soluble products (M2-SPs) for treating patients with cerebrovascular disease (CVD).

Materials and methods:

The protocol of the study was registered at www.ClinicalTrails.gov (NCT02957123). The study group comprised 30 patients with chronic CVD. Neurological status was examined before therapy and at 1- and 6-month follow–up. Concentrations of 32 cytokines in the blood serum were evaluated before and 1 month after therapy onset. Neurological assessment was conducted with the following scales: Subjective Assessment of Clinical (neurological) Symptoms (SACS), Hospital Anxiety and Depression Scale (HADS), Functional Mobility Assessment in Eldery Patients (FMA), and Montreal Cognitive Assessment (MoCa).

Results:

M2-SPs treatment (once daily for 28~30 days) was found to be safe and well tolerated. Neuropsychological improvements showed the amelioration of neurological symptoms, reduction in anxiety and depression levels, improvement in balance and gait ability as well as cognitive functions. Clinical effects could be detected at the end of treatment course and was stable during 6-month follow-up. Blood serum cytokine evaluation demonstrated diminished baseline levels of many cytokines including those with neurotrophic activity (brain-derived neurotrophic factor, BDNF; hepatocyte growth factor, HGF; migration inhibitory factor, MIF). Upon treatment, most pronounced clinical responses were observed in patients with most severe cytokine deficiency and post-therapy normalization of MIF and HGF levels.

Conclusion:

Intranasal therapy with M2-SPs is safe and according to preliminary data reduces neuropsychological deficit in patients with chronic CVD. The positive effect of M2-SPs treatment seems to be HGF- and MIF-dependent.