RP1, a RAGE antagonist peptide, can improve memory impairment and reduce Aβ plaque load in the APP/PS1 mouse model of Alzheimer's disease

Applications of the phage display technology in molecular biology, biotechnology and medicine

The phage display technology is based on the presentation of peptide sequences on the surface of virions of bacteriophages. Its development led to creation of sophisticated systems based on the possibility of the presentation of a huge variability of peptides, attached to one of proteins of bacteriophage capsids. The use of such systems allowed for achieving enormous advantages in the processes of selection of bioactive molecules. In fact, the phage display technology has been employed in numerous fields of biotechnology, as diverse as immunological and biomedical applications (in both diagnostics and therapy), the formation of novel materials, and many others. In this paper, contrary to many other review articles which were focussed on either specific display systems or the use of phage display in selected fields, we present a comprehensive overview of various possibilities of applications of this technology. We discuss an usefulness of the phage display technology in various fields of science, medicine and the broad sense of biotechnology. This overview indicates the spread and importance of applications of microbial systems (exemplified by the phage display technology), pointing to the possibility of developing such sophisticated tools when advanced molecular methods are used in microbiological studies, accompanied with understanding of details of structures and functions of microbial entities (bacteriophages in this case).

Electroacupuncture Improves Learning and Memory Abilities via Activating AMPK/mTOR-Induced Autophagy in APP/PS1 Mice

Alzheimer's disease (AD) has become a global public health problem characterized by memory and cognitive impairments. Electroacupuncture (EA) has been indicated to exert promising therapeutic effects on AD. This study aimed to further investigate the underlying mechanism of EA in AD treatment. APP/PS1 transgenic mice and wide-type mice underwent with or without EA treatment at GV20 and BL23 acupoints. Morris water maze test was utilized for examining the learning and memory of mice. Hematoxylin-eosin, Congo red, immunofluorescence, and TUNEL staining were employed for detecting the pathological changes of mouse brain hippocampus. Western blotting was implemented for measuring protein levels of autophagy- and AMPK/mTOR pathway-associated markers. APP/PS1 mice exhibited significant impairments in the spatial learning and memory. EA treatment improved the cognitive impairments, reduced amyloid-beta (Aβ) deposition, and alleviated neuronal apoptosis in the hippocampal tissues of APP/PS1 mice. EA promoted autophagy and activated the AMPK/mTOR signaling pathway in the hippocampus of APP/PS1 mice. EA improves the cognitive deficits, enhances Aβ clearance, and attenuates neuronal apoptosis in APP/PS1 mice in part by activating AMPK/mTOR-mediated autophagy.

Phage Display as a Medium for Target Therapy Based Drug Discovery, Review and Update

Phage libraries are now amongst the most prominent approaches for the identification of high-affinity antibodies/peptides from billions of displayed phages in a specific library through the biopanning process. Due to its ability to discover potential therapeutic candidates that bind specifically to targets, phage display has gained considerable attention in targeted therapy. Using this approach, peptides with high-affinity and specificity can be identified for potential therapeutic or diagnostic use. Furthermore, phage libraries can be used to rapidly screen and identify novel antibodies to develop immunotherapeutics. The Food and Drug Administration (FDA) has approved several phage display-derived peptides and antibodies for the treatment of different diseases. In the current review, we provided a comprehensive insight into the role of phage display-derived peptides and antibodies in the treatment of different diseases including cancers, infectious diseases and neurological disorders. We also explored the applications of phage display in targeted drug delivery, gene therapy, and CAR T-cell.

Cornuside ameliorates cognitive impairments via RAGE/TXNIP/NF-κB signaling in Aβ1-42 induced Alzheimer's disease mice

Cornuside has been discovered to improve learning and memory in AD mice, however, its underlying mechanism was not fully understood. In the present study, we established an AD mice model by intracerebroventricular injection of Aβ1-42, which were treated with cornuside (3, 10, 30 mg/kg) for 2 weeks. Cornuside significantly ameliorated cognitive function of AD mice in series of behavioral tests, including Morris water maze test, nest building test, novel object recognition test and step-down test. Additionally, cornuside could attenuate neuronal injury, and promote cholinergic synaptic transmission by restoring the level of acetylcholine (ACh) via inhibiting acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE), as well as facilitating choline acetyltransferase (ChAT). Furthermore, cornuside inhibited oxidative stress levels amplified as decreased malondialdehyde (MDA), by inhibiting TXNIP expression, improving total anti-oxidative capacity (TAOC), raising activities of superoxide dismutase (SOD) and catalase (CAT). Cornuside also reduced the activation of microglia and astrocytes, decreased the level of proinflammatory factors TNF-α, IL-6, IL-1β, iNOS and COX2 via interfering RAGE-mediated IKK-IκB-NF-κB phosphorylation. Similar anti-oxidative and anti-inflammatory effects were also found in LPS-stimulated BV2 cells via hampering RAGE-mediated TXNIP activation and NF-κB nuclear translocation. Virtual docking revealed that cornuside could interact with the active pocket of RAGE V domain directly. In conclusion, cornuside could bind to the RAGE directly impeding the interaction of Aβ and RAGE, and cut down the expression of TXNIP inhibiting ROS production and oxidative stress, as well as hamper NF-κB p65 mediated the inflammation.

Interactions between nanoparticles and pathological changes of vascular in Alzheimer's disease

Emerging evidence suggests that vascular pathological changes play a pivotal role in the pathogenesis of Alzheimer's disease (AD). The dysfunction of the cerebral vasculature occurs in the early course of AD, characterized by alterations in vascular morphology, diminished cerebral blood flow (CBF), impairment of the neurovascular unit (NVU), vasculature inflammation, and cerebral amyloid angiopathy. Vascular dysfunction not only facilitates the influx of neurotoxic substances into the brain, triggering inflammation and immune responses but also hampers the efflux of toxic proteins such as Aβ from the brain, thereby contributing to neurodegenerative changes in AD. Furthermore, these vascular changes significantly impact drug delivery and distribution within the brain. Therefore, developing targeted delivery systems or therapeutic strategies based on vascular alterations may potentially represent a novel breakthrough in AD treatment. This review comprehensively examines various aspects of vascular alterations in AD and outlines the current interactions between nanoparticles and pathological changes of vascular.

Blood-brain barrier transporters: An overview of function, dysfunction in Alzheimer's disease and strategies for treatment

The blood-brain-barrier (BBB) has a major function in maintaining brain homeostasis by regulating the entry of molecules from the blood to the brain. Key players in BBB function are BBB transporters which are highly expressed in brain endothelial cells (BECs) and critical in mediating the exchange of nutrients and waste products. BBB transporters can also influence drug delivery into the brain by inhibiting or facilitating the entry of brain targeting therapeutics for the treatment of brain disorders, such as Alzheimer's disease (AD). Recent studies have shown that AD is associated with a disrupted BBB and transporter dysfunction, although their roles in the development in AD are not fully understand. Modulation of BBB transporter activity may pose a novel approach to enhance the delivery of drugs to the brain for enhanced treatment of AD. In this review, we will give an overview of key functions of BBB transporters and known changes in AD. In addition, we will discuss current strategies for transporter modulation for enhanced drug delivery into the brain.

Ginsenoside Rg1 Attenuates Chronic Sleep Deprivation-Induced Hippocampal Mitochondrial Dysfunction and Improves Memory by the AMPK-SIRT3 Pathway

Ginsenoside Rg1 (Rg1) is the main bioactive ginseng component. This study investigates the effects of Rg1 on cognitive deficits triggered by chronic sleep deprivation stress (CSDS) and explores its underlying mechanisms. Rg1 effectively improved spatial working and recognition memory, as evidenced by various behavioral tests. RNA-sequence analysis revealed differential gene expression in the metabolic pathway. Treatment with Rg1 abrogated reductions in SOD and CAT activity, lowered MDA content, and increased Nrf2 and HO-1 protein levels. Rg1 administration alleviated hippocampal mitochondrial dysfunction by restoring normal ultrastructure and enhancing ATP activities and Mfn2 expression while regulating Drp-1 expression. Rg1 mitigated neuronal apoptosis by reducing the Bax/Bcl-2 ratio and the levels of cleaved caspase-3. Additionally, Rg1 upregulated AMPK and SIRT3 protein expressions. These findings suggest that Rg1 has potential as a robust intervention for cognitive dysfunction associated with sleep deprivation, acting through the modulation of mitochondrial function, oxidative stress, apoptosis, and the AMPK-SIRT3 axis.

Skin autofluorescence, reflecting accumulation of advanced glycation end products, and the risk of dementia in a population-based cohort

Conditions such as hyperglycemia and oxidative stress lead to the formation of advanced glycation end products (AGEs), which are harmful compounds that have been implicated in dementia. Within the Rotterdam Study, we measured skin AGEs as skin autofluorescence, reflecting long-term accumulation of AGEs, and determined their association with the risk of dementia and with brain magnetic resonance imaging (MRI) measures. Skin autofluorescence was measured between 2013 and 2016 in 2922 participants without dementia. Of these, 1504 also underwent brain MRI, on which measures of brain atrophy and cerebral small vessel disease were assessed. All participants were followed for the incidence of dementia until 2020. Of 2922 participants (mean age 72.6 years, 57% women), 123 developed dementia. Higher skin autofluorescence (per standard deviation) was associated with an increased risk of dementia (hazard ratio 1.21 [95% confidence interval 1.01-1.46]) and Alzheimer's disease (1.19 [0.97-1.47]), independently of age and other studied potential confounders. Stronger effects were seen in apolipoprotein E (APOE) ε4 carriers (1.34 [0.98-1.82]) and in participants with diabetes (1.35 [0.94-1.94]). Participants with higher skin autofluorescence levels also had smaller total brain volumes and smaller hippocampus volumes on MRI, and they had more often lacunes. These results suggest that AGEs may be involved in dementia pathophysiology.

In Silico Interactions of Natural and Synthetic Compounds with Key Proteins Involved in Alzheimer's Disease: Prospects for Designing New Therapeutics Compound

Memory impairment is a result of multiple factors including amyloid-beta (Aβ) accumulation. Several receptors are mediated for Aβ transport and signaling. Moreover, blood lipids are involved in Aβ signaling pathway through these receptors. Mediated blood lipid level by statins aims to regulate Aβ signaling cascade. First, the structure of receptors was taken from the RCSB PDB database and prepared with MGLTools and AutoDock tool 4. Second, the ligand was prepared for docking through AutoDock Vina. The binding affinity was calculated, and the binding sites were determined through LigPlot+ software. Besides, pharmacokinetic properties were calculated through multiple software. Finally, a molecular dynamics (MD) simulation was conducted to evaluate ligands stability along with clustering analysis to evaluate proteins connection. Our molecular docking and dynamic analyses revealed silymarin as a potential inhibitor of acetylcholinesterase (AChE), P-glycoprotein, and angiotensin-converting enzyme 2 (ACE2) with 0.704, 0.85, and 0.83 Å for RMSD along with -114.27, -107.44, and -122.51 kcal/mol for free binding energy, respectively. Moreover, rosuvastatin and quercetin have more stability compared to silymarin and donepezil in complex with P-glycoprotein and ACE2, respectively. Eventually, based on clustering and pharmacokinetics analysis, silymarin, rosuvastatin, and quercetin are suggested to be involved in peripheral clearance of Aβ. The bioactivity effects of mentioned statins and antioxidants are predicted to be helpful in treating memory impairment in Alzheimer's disease (AD). Nevertheless, mentioned drug effect could be improved by nanoparticles to facilitate penetration of the blood-brain barrier (BBB).

Regulation of beta-amyloid for the treatment of Alzheimer's disease: Research progress of therapeutic strategies and bioactive compounds

Alzheimer's disease (AD) is a progressive neurodegenerative disease that is difficult to treat. Extracellular amyloid is the principal pathological criterion for the diagnosis of AD. Amyloid β (Aβ) interacts with various receptor molecules on the plasma membrane and mediates a series of signaling pathways that play a vital role in the occurrence and development of AD. Research on receptors that interact with Aβ is currently ongoing. Overall, there are no effective medications to treat AD. In this review, we first discuss the importance of Aβ in the pathogenesis of AD, then summarize the latest progress of Aβ-related targets and compounds. Finally, we put forward the challenges and opportunities in the development of effective AD therapies.

AGE-TXNIP axis drives inflammation in Alzheimer's by targeting Aβ to mitochondria in microglia

Alzheimer's disease (AD) is the most common form of dementia characterized by progressive memory loss and cognitive decline. Although neuroinflammation and oxidative stress are well-recognized features of AD, their correlations with the early molecular events characterizing the pathology are not yet well clarified. Here, we characterize the role of RAGE-TXNIP axis in neuroinflammation in relation to amyloid-beta (Aβ) burden in both in vivo and in vitro models. In the hippocampus of 5xFAD mice microglial activation, cytokine secretion, and glial fibrillary acidic protein-enhanced expression are paralleled with increased TXNIP expression. TXNIP silencing or its pharmacological inhibition prevents neuroinflammation in those mice. TXNIP is also associated with RAGE and Aβ. In particular, RAGE-TXNIP axis is required for targeting Aβ in mitochondria, leading to mitochondrial dysfunction and oxidative stress. Silencing of TXNIP or inhibition of RAGE activation reduces Aβ transport from the cellular surface to mitochondria, restores mitochondrial functionality, and mitigates Aβ toxicity. Furthermore, Aβ shuttling into mitochondria promotes Drp1 activation and exacerbates mitochondrial dysfunction, which induces NLRP3 inflammasome activation, leading to secretion of IL-1β and activation of the pyroptosis-associated protein Gasdermin D (GSDMD). Downregulation of RAGE-TXNIP axis inhibits Aβ-induced mitochondria dysfunction, inflammation, and induction of GSDMD. Herein we unveil a new pathway driven by TXNIP that links the mitochondrial transport of Aβ to the activation of Drp1 and the NLRP3 inflammasome, promoting the secretion of IL-1β and the pyroptosis pathway associated with GSDMD cleavage. Altogether these data shed new light on a novel mechanism of action of RAGE-TXNIP axis in microglia, which is intertwined with Aβ and ultimately causes mitochondria dysfunction and NLRP3 inflammasome cascade activation, suggesting TXNIP as a druggable target to be better deepened for AD.

The nanotechnological approach for nasal delivery of peptide drugs: a comprehensive review

This review gathers recent studies, patents, and clinical trials involving the nasal administration of peptide drugs to supply a panorama of developing nanomedicine advances in this field. Peptide drugs have been featured in the pharmaceutical market, due to their high efficacy, biological activity, and low immunogenicity. Pharmaceutical industries need technology to circumvent issues relating to peptide stability and bioavailability. The oral route offers very harsh and unfavourable conditions for peptide administration, while the parenteral route is inconvenient and risky for patients. Nasal administration is an attractive alternative, mainly when associated with nanotechnological approaches. Nanomedicines may improve the nasal administration of peptide drugs by providing protection for the macromolecules from enzymes while also increasing their time of retention and permeability in the nasal mucosa. Nanomedicines for nasal administration containing peptide drugs have been acclaimed for both prevention, and treatment, of infections, including the pandemic COVID-19, cancers, metabolic and neurodegenerative diseases.

Amyloidosis in Alzheimer's Disease: Pathogeny, Etiology, and Related Therapeutic Directions

The amyloid hypothesis of Alzheimer’s disease has long been the predominant theory, suggesting that Alzheimer’s disease is caused by the accumulation of amyloid beta protein (Aβ) in the brain, leading to neuronal toxicity in the central nervous system (CNS). Because of breakthroughs in molecular medicine, the amyloid pathway is thought to be central to the pathophysiology of Alzheimer’s disease (AD). Currently, it is believed that altered biochemistry of the Aβ cycle remains a central biological feature of AD and is a promising target for treatment. This review provides an overview of the process of amyloid formation, explaining the transition from amyloid precursor protein to amyloid beta protein. Moreover, we also reveal the relationship between autophagy, cerebral blood flow, ACHE, expression of LRP1, and amyloidosis. In addition, we discuss the detailed pathogenesis of amyloidosis, including oxidative damage, tau protein, NFTs, and neuronal damage. Finally, we list some ways to treat AD in terms of decreasing the accumulation of Aβ in the brain.

Nose-to-brain drug delivery for the treatment of Alzheimer's Disease: Current advancements and challenges

INTRODUCTION

The irreversible destruction of neurons, progressive loss of memory and cognitive behavior, high cost of therapy, and impact on society desire a better, effective, and affordable treatment of AD. The nose-to-brain drug delivery approach holds a great potential to access the brain without any hindrance of BBB and result in higher bioavailability thus better therapeutic efficacy of anti-AD drugs.

AREAS COVERED

The present review article highlighted the current facts and worldwide statistics of AD and its detailed etiology. Followed by barriers to brain delivery, nose-to-brain delivery, their limitations, and amalgamation with various novel carrier systems. We have emphasized recent advancements in nose-to-brain delivery using mucoadhesive, stimuli-responsive carriers, polymeric nanoparticles, lipid nanoparticles, protein/peptide delivery for treatment of AD.

EXPERT OPINION

The available therapies are symptomatic, mitigate the symptoms of AD at the initial stages. In this lieu, nose-to-brain delivery has the ability to overcome these limitations and increase drug bioavailability in the brain. Various novel strategies including stimuli-responsive systems, nanoparticles, etc. enhance the nasal drug permeation, protects the drug, and enhance its therapeutic potency. Although, successful preclinical data does not assure the clinical success of the therapy and hence exhaustive clinical investigations are needed to make the therapy available for patients.

Improvement of electroacupuncture on APP/PS1 transgenic mice in behavioral probably due to reducing deposition of Aβ in hippocampus

Alzheimer's disease (AD) is a fatal neurodegenerative disease for which currently no cure is available. Electroacupuncture (EA) has been widely used in China as an alternative therapeutic approach for neurological diseases. The cognitive decline in patients with AD has been reported to be closely related to the deposition of amyloid-β (Aβ) in the hippocampus of the brain, and the Morris water maze (MWM) test is a widely used method for assessing the behavior of animal models. In this study, the MWM test was performed to evaluate the effects of EA treatment on cognitive function and memory, and the micro-positron emission tomography scan was used to assess the hippocampal Aβ deposition. The results showed that the cognitive function of APP/PS1 mice was significantly improved and the rate of [18F]AV-45 uptake was reduced in the EA group, compared with the AD group. Our study suggested that EA can exert a therapeutic effect in AD by improving spatial learning and memory and inhibiting the hippocampal Aβ deposition.

Relationship Between Amyloid-β Deposition and Blood-Brain Barrier Dysfunction in Alzheimer's Disease

Amyloid-β (Aβ) is the predominant pathologic protein in Alzheimer's disease (AD). The production and deposition of Aβ are important factors affecting AD progression and prognosis. The deposition of neurotoxic Aβ contributes to damage of the blood-brain barrier. However, the BBB is also crucial in maintaining the normal metabolism of Aβ, and dysfunction of the BBB aggravates Aβ deposition. This review characterizes Aβ deposition and BBB damage in AD, summarizes their interactions, and details their respective mechanisms.

Delivery of MiRNA-92a Inhibitor Using RP1-Linked Peptide Elicits Anti-Inflammatory Effects in an Acute Lung Injury Model

Acute lung injury (ALI) is an inflammatory lung disease. miRNA-92a (miR92a) is induced in the lungs of ALI patients and mediates inflammatory reactions. In this study, a RP1-linked R3V6 (RP1R3V6) peptide was synthesized and evaluated as a carrier of anti-microRNA-92a oligonucleotide (AMO92a) into the lungs of an ALI animal model. In addition to the carrier function, the RP1-linked peptide can have anti-inflammatory effects in the lungs, since RP1 is an antagonist of the receptors for advanced glycation end-products (RAGEs). In a gel retardation assay, the RP1R3V6 peptide formed a spherical complex with AMO92a. In an in vitro delivery assay to L2 rat lung epithelial cells, RP1R3V6 had a lower AMO92a delivery efficiency than R3V6 and polyethyleneimine (PEI25k; 25 kDa). However, RP1R3V6 had an additional anti-inflammatory effect, reducing tumor necrosis factor-α (TNF-α) in lipopolysaccharide-activatedmacrophage cells. With the combined effects of AMO92a and RP1, the RP1R3V6/AMO92a complex reduced the miR92a level more efficiently than did the R3V6/AMO92a and PEI25k/AMO92a complexes. The RP1R3V6/AMO92a complex was administered into the lungs of ALI animals by intratracheal instillation. As a result, the expression of phosphatase and tensin homolog, a target of miR92a, was increased in the lungs. Furthermore, the RP1R3V6/AMO92a complex decreased the TNF-α and interleukin-1β (IL-1β) levels more efficiently than did the PEI25k/AMO92a and R3V6/AMO92a complexes, decreasing the damage in the lungs. These results suggest that RP1R3V6 is a useful carrier of AMO92a and has anti-inflammatory effects in an ALI animal model.

Impact of Gut Microbiome Manipulation in 5xFAD Mice on Alzheimer's Disease-Like Pathology

The gut brain axis seems to modulate various psychiatric and neurological disorders such as Alzheimer's disease (AD). Growing evidence has led to the assumption that the gut microbiome might contribute to or even present the nucleus of origin for these diseases. In this regard, modifiers of the microbial composition might provide attractive new therapeutics. Aim of our study was to elucidate the effect of a rigorously changed gut microbiome on pathological hallmarks of AD. 5xFAD model mice were treated by antibiotics or probiotics (L. acidophilus and L. rhamnosus) for 14 weeks. Pathogenesis was measured by nest building capability and plaque deposition. The gut microbiome was affected as expected: antibiotics significantly reduced viable commensals, while probiotics transiently increased Lactobacillaceae. Nesting score, however, was only improved in antibiotics-treated mice. These animals additionally displayed reduced plaque load in the hippocampus. While various physiological parameters were not affected, blood sugar was reduced and serum glucagon level significantly elevated in the antibiotics-treated animals together with a reduction in the receptor for advanced glycation end products RAGE-the inward transporter of Aβ peptides of the brain. Assumedly, the beneficial effect of the antibiotics was based on their anti-diabetic potential.