Subsequent correlated changes in complement component 3 and amyloid beta oligomers in the blood of patients with Alzheimer's disease

INTRODUCTION

Alzheimer's disease (AD) involves the complement cascade, with complement component 3 (C3) playing a key role. However, the relationship between C3 and amyloid beta (Aβ) in blood is limited.

METHODS

Plasma C3 and Aβ oligomerization tendency (AβOt) were measured in 35 AD patients and 62 healthy controls. Correlations with cerebrospinal fluid (CSF) biomarkers, cognitive impairment, and amyloid positron emission tomography (PET) were analyzed. Differences between biomarkers were compared in groups classified by concordances of biomarkers.

RESULTS

Plasma C3 and AβOt were elevated in AD patients and in CSF or amyloid PET-positive groups. Weak positive correlation was found between C3 and AβOt, while both had strong negative correlations with CSF Aβ42 and cognitive performance. Abnormalities were observed for AβOt and CSF Aβ42 followed by C3 changes.

DISCUSSION

Increased plasma C3 in AD are associated with amyloid pathology, possibly reflecting a defense response for Aβ clearance. Further studies on Aβ-binding proteins will enhance understanding of Aβ mechanisms in blood.

Assessment of acetylcholinesterase activity in CD9-positive exosomes from patients with Parkinson's disease

Introduction

Parkinson's disease (PD) is a neurodegenerative disorder characterized by dopaminergic dysfunction and associated with abnormalities in the cholinergic system. However, the relationship between PD and cholinergic dysfunction, particularly in exosomes, is not fully understood.

Methods

We enrolled 37 patients with PD and 44 healthy controls (HC) to investigate acetylcholinesterase (AChE) activity in CD9-positive and L1CAM-positive exosomes. Exosomes were isolated from plasma using antibody-coupled magnetic beads, and their sizes and concentrations were assessed using transmission electron microscopy, nanoparticle tracking analysis, and western blotting. Subsequently, the AChE activity in these exosomes was analyzed in relation to various clinical parameters.

Results

A significant decrease in AChE activity was observed in CD9-positive exosomes derived from patients with PD, whereas no significant differences were found in L1CAM-positive exosomes. Further analysis with a larger sample size confirmed a substantial reduction in AChE activity in CD9-positive exosomes from the PD plasma, with moderate diagnostic accuracy. The decrease in AChE activity of CD9-positive exosomes did not show an association with cognitive impairment but displayed a trend toward correlation with PD progression.

Discussion

The reduction in AChE activity in CD9-positive exosomes suggests potential peripheral cholinergic dysfunction in PD, independent of the central cholinergic system. The observed alterations in AChE activity provide valuable insights into the association between cholinergic dysfunction and the pathogenesis of PD.

Unique Bioactives from Zombie Fungus (Cordyceps) as Promising Multitargeted Neuroprotective Agents

Cordyceps, also known as "zombie fungus", is a non-poisonous mushroom that parasitizes insects for growth and development by manipulating the host system in a way that makes the victim behave like a "zombie". These species produce promising bioactive metabolites, like adenosine, β-glucans, cordycepin, and ergosterol. Cordyceps has been used in traditional medicine due to its immense health benefits, as it boosts stamina, appetite, immunity, longevity, libido, memory, and sleep. Neuronal loss is the typical feature of neurodegenerative diseases (NDs) (Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS)) and neurotrauma. Both these conditions share common pathophysiological features, like oxidative stress, neuroinflammation, and glutamatergic excitotoxicity. Cordyceps bioactives (adenosine, N6-(2-hydroxyethyl)-adenosine, ergosta-7, 9 (11), 22-trien-3β-ol, active peptides, and polysaccharides) exert potential antioxidant, anti-inflammatory, and anti-apoptotic activities and display beneficial effects in the management and/or treatment of neurodegenerative disorders in vitro and in vivo. Although a considerable list of compounds is available from Cordyceps, only a few have been evaluated for their neuroprotective potential and still lack information for clinical trials. In this review, the neuroprotective mechanisms and safety profile of Cordyceps extracts/bioactives have been discussed, which might be helpful in the identification of novel potential therapeutic entities in the future.

PSEN1 His214Asn Mutation in a Korean Patient with Familial EOAD and the Importance of Histidine-Tryptophan Interactions in TM-4 Stability

A pathogenic mutation in presenilin-1 (PSEN1), His214Asn, was found in a male patient with memory decline at the age of 41 in Korea for the first time. The proband patient was associated with a positive family history from his father, paternal aunt, and paternal grandmother without genetic testing. He was diagnosed with early onset Alzheimer's disease (EOAD). PSEN1 His214Asn was initially reported in an Italian family, where the patient developed phenotypes similar to the current proband patient. Magnetic resonance imaging (MRI) scans revealed a mild hippocampal atrophy. The amyloid positron emission tomography (amyloid-PET) was positive, along with the positive test results of the increased amyloid ß (Aβ) oligomerization tendency with blood. The PSEN1 His214 amino acid position plays a significant role in the gamma-secretase function, especially from three additional reported mutations in this residue: His214Asp, His214Tyr, and His214Arg. The structure prediction model revealed that PSEN1 protein His214 may interact with Trp215 of His-Trp cation-π interaction, and the mutations of His214 would destroy this interaction. The His-Trp cation-π interaction between His214 and Trp215 would play a crucial structural role in stabilizing the 4th transmembrane domain of PSEN1 protein, especially when aromatic residues were often reported in the membrane interface of the lipid-extracellular region of alpha helices or beta sheets. The His214Asn would alter the cleavage dynamics of gamma-secretase from the disappeared interactions between His214 and Trp215 inside of the helix, resulting in elevated amyloid production. Hence, the increased Aβ was reflected in the increased Aβ oligomerization tendency and the accumulations of Aβ in the brain from amyloid-PET, leading to EOAD.

Trachyspermum ammi Bioactives Promote Neuroprotection by Inhibiting Acetylcholinesterase, Aβ-Oligomerization/Fibrilization, and Mitigating Oxidative Stress In Vitro

Neurodegenerative diseases (NDs) are a large category of progressive neurological disorders with diverse clinical and pathological characteristics. Among the NDs, Alzheimer's disease (AD) is the most widespread disease, which affects more than 400 million people globally. Oxidative stress is evident in the pathophysiology of nearly all NDs by affecting several pathways in neurodegeneration. No single drug can manage multi-faceted diseases like NDs. Therefore, an alternative therapeutic strategy is required, which can affect several pathophysiological pathways at a time. To achieve this aim, hexane and ethyl acetate extract from Trachyspermum ammi (Carom) were prepared, and GC/MS identified the bioactive compounds. For the cell-based assays, oxidative stress was induced in SH-SY5Y neuroblastoma cells using hydrogen peroxide to evaluate the neuroprotective potential of the Carom extracts/bioactives. The extracts/bioactives provided neuroprotection in the cells by modulating multiple pathways involved in neurodegeneration, such as alleviating oxidative stress and mitochondrial membrane potential. They were potent inhibitors of acetylcholine esterase enzymes and displayed competitive/mixed-type inhibition. Additionally, anti-Aβ1-42 fibrilization/oligomerization and anti-glycation activities were also analyzed. The multi-faceted neuroprotection shown via Carom/Carvacrol makes it a prospective contender in drug development for NDs.

Patient with PSEN1 Glu318Gly and Other Possible Disease Risk Mutations, Diagnosed with Early Onset Alzheimer's Disease

In this manuscript, we introduced a French EOAD patient in Korea who carried the presenilin-1 (PSEN1) Glu318Gly mutations with four possible risk variants, including sortilin-related receptor 1 (SORL1) Glu270Lys, ATP-binding cassette subfamily A member 7 (ABCA7) Val1946Met, translocase of outer mitochondrial membrane 40 (TOMM40) Arg239Trp, and granulin (GRN) Ala505Gly. The patient started to present memory decline and behavioral dysfunction in his early 60s. His brain imaging presented amyloid deposits by positron emission tomography (PET-CT). The multimer detection system (MDS) screening test for plasma for amyloid oligomers was also positive, which supported the AD diagnosis. It was verified that PSEN1 Glu318Gly itself may not impact amyloid production. However, additional variants were found in other AD and non-AD risk genes, as follows: SORL1 Glu270Lys was suggested as a risk mutation for AD and could increase amyloid peptide production and impair endosome functions. ABCA7 Val1946Met was a novel variant that was predicted to be damaging. The GRN Ala505Gly was a variant with uncertain significance; however, it may reduce the granulin levels in the plasma of dementia patients. Pathway analysis revealed that PSEN1 Glu318Gly may work as a risk factor along with the SORL1 and ABCA7 variants since pathway analysis revealed that PSEN1 could directly interact with them through amyloid-related and lipid metabolism pathways. TOMM40 and PSEN1 could have common mechanisms through mitochondrial dysfunction. It may be possible that PSEN1 Glu318Gly and GRN Ala505Gly would impact disease by impairing immune-related pathways, including microglia and astrocyte development, or NFkB-related pathways. Taken together, the five risk factors may contribute to disease-related pathways, including amyloid and lipid metabolism, or impair immune mechanisms.

Mammalian Models in Alzheimer's Research: An Update

A form of dementia distinct from healthy cognitive aging, Alzheimer's disease (AD) is a complex multi-stage disease that currently afflicts over 50 million people worldwide. Unfortunately, previous therapeutic strategies developed from murine models emulating different aspects of AD pathogenesis were limited. Consequently, researchers are now developing models that express several aspects of pathogenesis that better reflect the clinical situation in humans. As such, this review seeks to provide insight regarding current applications of mammalian models in AD research by addressing recent developments and characterizations of prominent transgenic models and their contributions to pathogenesis as well as discuss the advantages, limitations, and application of emerging models that better capture genetic heterogeneity and mixed pathologies observed in the clinical situation.

Increased oligomeric TDP-43 in the plasma of Korean frontotemporal dementia patients with semantic dementia

INTRODUCTION

Semantic dementia (SD) is a progressive neurodegenerative disease associated with impaired vocabulary that progresses to memory impairment. Post-mortem immunohistochemical analysis is the current reliable method of differentiating TDP-43 deposits in cortical tissue; no means of antemortem diagnosis exists in biofluids, let alone in plasma.

METHODS

Here the multimer detection system (MDS) was used to quantify the oligomeric TDP-43 (o-TDP-43) concentrations in plasma of Korean SD patients (n = 16, 6 male, 10 female, ages 59-87). The o-TDP-43 concentrations were compared with the total TDP-43 (t-TDP-43) concentrations quantified through conventional enzyme-linked immunosorbent assay (ELISA).

RESULTS AND DISCUSSION

Only MDS showed a significant increase in o-TDP-43 concentrations in the plasma of patients with SD compared to other neurodegenerative disorders and normal controls (p < 0.05). Based on these results, o-TDP-43 concentrations through the application of MDS may be a useful plasma biomarker in SD-FTD (frontotemporal dementia) diagnosis.

Studies of Genetic and Proteomic Risk Factors of Amyotrophic Lateral Sclerosis Inspire Biomarker Development and Gene Therapy

Amyotrophic lateral sclerosis (ALS) is an incurable neurodegenerative disease affecting the upper and lower motor neurons, leading to muscle weakness, motor impairments, disabilities and death. Approximately 5-10% of ALS cases are associated with positive family history (familial ALS or fALS), whilst the remainder are sporadic (sporadic ALS, sALS). At least 50 genes have been identified as causative or risk factors for ALS. Established pathogenic variants include superoxide dismutase type 1 (SOD1), chromosome 9 open reading frame 72 (c9orf72), TAR DNA Binding Protein (TARDBP), and Fused In Sarcoma (FUS); additional ALS-related genes including Charged Multivesicular Body Protein 2B (CHMP2B), Senataxin (SETX), Sequestosome 1 (SQSTM1), TANK Binding Kinase 1 (TBK1) and NIMA Related Kinase 1 (NEK1), have been identified. Mutations in these genes could impair different mechanisms, including vesicle transport, autophagy, and cytoskeletal or mitochondrial functions. So far, there is no effective therapy against ALS. Thus, early diagnosis and disease risk predictions remain one of the best options against ALS symptomologies. Proteomic biomarkers, microRNAs, and extracellular vehicles (EVs) serve as promising tools for disease diagnosis or progression assessment. These markers are relatively easy to obtain from blood or cerebrospinal fluids and can be used to identify potential genetic causative and risk factors even in the preclinical stage before symptoms appear. In addition, antisense oligonucleotides and RNA gene therapies have successfully been employed against other diseases, such as childhood-onset spinal muscular atrophy (SMA), which could also give hope to ALS patients. Therefore, an effective gene and biomarker panel should be generated for potentially "at risk" individuals to provide timely interventions and better treatment outcomes for ALS patients as soon as possible.

Black Pepper (Piper nigrum) Alleviates Oxidative Stress, Exerts Potential Anti-Glycation and Anti-AChE Activity: A Multitargeting Neuroprotective Agent against Neurodegenerative Diseases

Neurodegenerative diseases (NDs) are a family of disorders that cause progressive structural and functional degeneration of neurons. Among all the organs in the body, the brain is the one that is the most affected by the production and accumulation of ROS. Various studies have shown that an increase in oxidative stress is a common pathophysiology for almost all NDs, which further affects various other pathways. The available drugs lack the wide spectrum necessary to confront these complexities altogether. Hence, a safe therapeutic approach to target multiple pathways is highly desirable. In the present study, the hexane and ethyl acetate extracts of Piper nigrum (black pepper), an important spice, were evaluated for their neuroprotective potential in hydrogen peroxide-induced oxidative stress in human neuroblastoma cells (SH-SY5Y). The extracts were also subjected to GC/MS to identify the important bioactives present. The extracts exhibited neuroprotection by significantly decreasing the oxidative stress and restoring the mitochondrial membrane potential in the cells. Additionally, the extracts displayed potent anti-glycation and significant anti-Aβ fibrilization activities. The extracts were competitive inhibitors of AChE. The multitarget neuroprotective mechanism displayed by Piper nigrum indicates it as a potential candidate in the treatment of NDs.

Presenilin-1 (PSEN1) Mutations: Clinical Phenotypes beyond Alzheimer's Disease

Presenilin 1 (PSEN1) is a part of the gamma secretase complex with several interacting substrates, including amyloid precursor protein (APP), Notch, adhesion proteins and beta catenin. PSEN1 has been extensively studied in neurodegeneration, and more than 300 PSEN1 mutations have been discovered to date. In addition to the classical early onset Alzheimer's disease (EOAD) phenotypes, PSEN1 mutations were discovered in several atypical AD or non-AD phenotypes, such as frontotemporal dementia (FTD), Parkinson's disease (PD), dementia with Lewy bodies (DLB) or spastic paraparesis (SP). For example, Leu113Pro, Leu226Phe, Met233Leu and an Arg352 duplication were discovered in patients with FTD, while Pro436Gln, Arg278Gln and Pro284Leu mutations were also reported in patients with motor dysfunctions. Interestingly, PSEN1 mutations may also impact non-neurodegenerative phenotypes, including PSEN1 Pro242fs, which could cause acne inversa, while Asp333Gly was reported in a family with dilated cardiomyopathy. The phenotypic diversity suggests that PSEN1 may be responsible for atypical disease phenotypes or types of disease other than AD. Taken together, neurodegenerative diseases such as AD, PD, DLB and FTD may share several common hallmarks (cognitive and motor impairment, associated with abnormal protein aggregates). These findings suggested that PSEN1 may interact with risk modifiers, which may result in alternative disease phenotypes such as DLB or FTD phenotypes, or through less-dominant amyloid pathways. Next-generation sequencing and/or biomarker analysis may be essential in clearly differentiating the possible disease phenotypes and pathways associated with non-AD phenotypes.

Multi-Targeting Neuroprotective Effects of Syzygium aromaticum Bud Extracts and Their Key Phytocompounds against Neurodegenerative Diseases

Alzheimer's disease (AD) is a neurodegenerative disease that causes a gradual loss of normal motor and cognitive function. The complex AD pathophysiology involves various factors such as oxidative stress, neuroinflammation, amyloid-beta (Aβ) aggregation, disturbed neurotransmission, and apoptosis. The available drugs suffer from a range of side effects and are not able to cover different aspects of the disease. Therefore, finding a safer therapeutic approach that can affect multiple targets at a time is highly desirable. In the present study, the underlying neuroprotective mechanism of an important culinary spice, Syzygium aromaticum (Clove) extract, and major bioactive compounds were studied in hydrogen peroxide-induced oxidative stress in human neuroblastoma SH-SY5Y cell lines as a model. The extracts were subjected to GC-MS to identify important bioactive components. The extracts and key bio-actives reduced reactive oxygen species (ROS), restored mitochondrial membrane potential (MMP), and provided neuroprotection from H2O2-induced oxidative stress in cell-based assays due to the antioxidant action. They also reduced lipid peroxidation significantly and restored GSH content. Clove extracts have also displayed anti-acetylcholinesterase (AChE) activity, anti-glycation potential, and Aβ aggregation/fibrilization inhibition. The multitarget neuroprotective approach displayed by Clove makes it a potential candidate for AD drug development.

Double Mutations in a Patient with Early-Onset Alzheimer's Disease in Korea: An APP Val551Met and a PSEN2 His169Asn

The etiology of early-onset Alzheimer's disease (EOAD) is associated with alterations in the production of amyloid beta (Aβ) species caused by mutations in the APP, PSEN1, and PSEN2 genes. Mutations affect intra- or inter-molecular interactions and processes between the γ-secretase complex and amyloid precursor protein (APP), leading to the aberrant sequential cleavage of Aβ species. A 64-year-old woman presented with progressive memory decline, mild right hippocampal atrophy, and a family history of Alzheimer's dementia (AD). Whole exome sequencing was performed to evaluate AD-related gene mutations, which were verified by Sanger sequencing. A mutation-caused structural alteration of APP was predicted using in silico prediction programs. Two AD-related mutations, in APP (rs761339914; c.G1651A; p.V551M) and PSEN2 (rs533813519; c.C505A; p.H169N), were identified. The APP Val551Met mutation in the E2 domain may influence APP homodimerization through changes in intramolecular interactions between adjacent amino acids, altering Aβ production. The second mutation was PSEN2 His169Asn mutation, which was previously reported in five EOAD patients from Korea and China, with a relatively high frequency in the East Asian population. According to a previous report, the presenilin 2 protein was predicted to result in a major helical torsion by PSEN2 His169Asn mutation. Notably, the co-existence of APP Val551Met and PSEN2 His169Asn may induce a synergistic effect by both mutations. Future functional studies are needed to clarify the pathological effects of these double mutations.

Erratum: Plasma Oligomeric Beta Amyloid in Alzheimer's Disease with History of Agent Orange Exposure

[This corrects the article on p. 41 in vol. 17, PMID: 30906391.].

Alpha-synuclein: a pathological factor with Aβ and tau and biomarker in Alzheimer's disease

BACKGROUND

Alpha-synuclein (α-syn) is considered the main pathophysiological protein component of Lewy bodies in synucleinopathies. α-Syn is an intrinsically disordered protein (IDP), and several types of structural conformations have been reported, depending on environmental factors. Since IDPs may have distinctive functions depending on their structures, α-syn can play different roles and interact with several proteins, including amyloid-beta (Aβ) and tau, in Alzheimer's disease (AD) and other neurodegenerative disorders.

MAIN BODY

In previous studies, α-syn aggregates in AD brains suggested a close relationship between AD and α-syn. In addition, α-syn directly interacts with Aβ and tau, promoting mutual aggregation and exacerbating the cognitive decline. The interaction of α-syn with Aβ and tau presented different consequences depending on the structural forms of the proteins. In AD, α-syn and tau levels in CSF were both elevated and revealed a high positive correlation. Especially, the CSF α-syn concentration was significantly elevated in the early stages of AD. Therefore, it could be a diagnostic marker of AD and help distinguish AD from other neurodegenerative disorders by incorporating other biomarkers.

CONCLUSION

The overall physiological and pathophysiological functions, structures, and genetics of α-syn in AD are reviewed and summarized. The numerous associations of α-syn with Aβ and tau suggested the significance of α-syn, as a partner of the pathophysiological roles in AD. Understanding the involvements of α-syn in the pathology of Aβ and tau could help address the unresolved issues of AD. In particular, the current status of the CSF α-syn in AD recommends it as an additional biomarker in the panel for AD diagnosis.

Prion Mutations in Republic of Republic of Korea, China, and Japan

Prion gene (PRNP) mutations are associated with diverse disease phenotypes, including familiar Creutzfeldt-Jakob Disease (CJD), Gerstmann-Sträussler-Scheinker disease (GSS), and fatal familial insomnia (FFI). Interestingly, PRNP mutations have been reported in patients diagnosed with Alzheimer's disease, dementia with Lewy bodies, Parkinson's disease, and frontotemporal dementia. In this review, we describe prion mutations in Asian countries, including Republic of Republic of Korea, China, and Japan. Clinical phenotypes and imaging data related to these mutations have also been introduced in detail. Several prion mutations are specific to Asians and have rarely been reported in countries outside Asia. For example, PRNP V180I and M232R, which are rare in other countries, are frequently detected in Republic of Korea and Japan. PRNP T188K is common in China, and E200K is significantly more common among Libyan Jews in Israel. The A117V mutation has not been detected in any Asian population, although it is commonly reported among European GSS patients. In addition, V210I or octapeptide insertion is common among European CJD patients, but relatively rare among Asian patients. The reason for these differences may be geographical or ethical isolation. In terms of clinical phenotypes, V180I, P102L, and E200K present diverse clinical symptoms with disease duration, which could be due to other genetic and environmental influences. For example, rs189305274 in the ACO1 gene may be associated with neuroprotective effects in cases of V180I mutation, leading to longer disease survival. Additional neuroprotective variants may be possible in cases featuring the E200K mutation, such as KLKB1, KARS, NRXN2, LAMA3, or CYP4X1. E219K has been suggested to modify the disease course in cases featuring the P102L mutation, as it may result in the absence of prion protein-positive plaques in tissue stained with Congo red. However, these studies analyzed only a few patients and may be too preliminary. The findings need to be verified in studies with larger sample sizes or in other populations. It would be interesting to probe additional genetic factors that cause disease progression or act as neuroprotective factors. Further studies are needed on genetic modifiers working with prions and alterations from mutations.

Prion therapeutics: Lessons from the past

Prion diseases are a group of incurable zoonotic neurodegenerative diseases (NDDs) in humans and other animals caused by the prion proteins. The abnormal folding and aggregation of the soluble cellular prion proteins (PrPC) into scrapie isoform (PrPSc) in the Central nervous system (CNS) resulted in brain damage and other neurological symptoms. Different therapeutic approaches, including stalling PrPC to PrPSc conversion, increasing PrPSc removal, and PrPC stabilization, for which a spectrum of compounds, ranging from organic compounds to antibodies, have been explored. Additionally, a non-PrP targeted drug strategy using serpin inhibitors has been discussed. Despite numerous scaffolds being screened for anti-prion activity in vitro, only a few were effective in vivo and unfortunately, almost none of them proved effective in the clinical studies, most likely due to toxicity and lack of permeability. Recently, encouraging results from a prion-protein monoclonal antibody, PRN100, were presented in the first human trial on CJD patients, which gives a hope for better future for the discovery of other new molecules to treat prion diseases. In this comprehensive review, we have re-visited the history and discussed various classes of anti-prion agents, their structure, mode of action, and toxicity. Understanding pathogenesis would be vital for developing future treatments for prion diseases. Based on the outcomes of existing therapies, new anti-prion agents could be identified/synthesized/designed with reduced toxicity and increased bioavailability, which could probably be effective in treating prion diseases.

Pandanus amaryllifolius Exhibits In Vitro Anti-Amyloidogenic Activity and Promotes Neuroprotective Effects in Amyloid-β-Induced SH-SY5Y Cells

Accumulation of amyloid-beta (Aβ) plaques leading to oxidative stress, mitochondrial damage, and cell death is one of the most accepted pathological hallmarks of Alzheimer’s disease (AD). Pandanus amaryllifolius, commonly recognized as fragrant screw pine due to its characteristic smell, is widely distributed in Southeast Asia and is consumed as a food flavor. In search for potential anti-AD agents from terrestrial sources, P. amaryllifolius was explored for its in vitro anti-amyloidogenic and neuroprotective effects. Thioflavin T (ThT) assay and the high-throughput screening multimer detection system (MDS-HTS) assay were used to evaluate the extracts’ potential to inhibit Aβ aggregations and oligomerizations, respectively. The crude alcoholic extract (CAE, 50 μg/mL) and crude base extract (CBE, 50 μg/mL) obstructed the Aβ aggregation. Interestingly, results revealed that only CBE inhibited the Aβ nucleation at 100 μg/mL. Both CAE and CBE also restored the cell viability, reduced the level of reactive oxygen species, and reversed the mitochondrial dysfunctions at 10 and 20 μg/mL extract concentrations in Aβ-insulted SY-SY5Y cells. In addition, the unprecedented isolation of nicotinamide from P. amaryllifolius CBE is a remarkable discovery as one of its potential bioactive constituents against AD. Hence, our results provided new insights into the promising potential of P. amaryllifolius extracts against AD and further exploration of other prospective bioactive constituents.

Beauty of the beast: anticholinergic tropane alkaloids in therapeutics

Tropane alkaloids (TAs) are among the most valued chemical compounds known since pre-historic times. Poisonous plants from Solanaceae family (Hyoscyamus niger, Datura, Atropa belladonna, Scopolia lurida, Mandragora officinarum, Duboisia) and Erythroxylaceae (Erythroxylum coca) are rich sources of tropane alkaloids. These compounds possess the anticholinergic properties as they could block the neurotransmitter acetylcholine action in the central and peripheral nervous system by binding at either muscarinic and/or nicotinic receptors. Hence, they are of great clinical importance and are used as antiemetics, anesthetics, antispasmodics, bronchodilator and mydriatics. They also serve as the lead compounds to generate more effective drugs. Due to the important pharmacological action they are listed in the WHO list of essential medicines and are available in market with FDA approval. However, being anticholinergic in action, TA medication are under the suspicion of causing dementia and cognitive decline like other medications with anticholinergic action, interestingly which is incorrect. There are published reviews on chemistry, biosynthesis, pharmacology, safety concerns, biotechnological aspects of TAs but the detailed information on anticholinergic mechanism of action, clinical pharmacology, FDA approval and anticholinergic burden is lacking. Hence the present review tries to fill this lacuna by critically summarizing and discussing the above mentioned aspects.

Whole Exome Sequencing Reveals a Novel APOE Mutation in a Patient With Sporadic Early-Onset Alzheimer's Disease

Apolipoprotein (APOE) is implicated and verified as the main risk factor for early-onset Alzheimer's disease (AD). APOE is a protein that binds to lipids and is involved in cholesterol stability. Our paper reports a case of a sporadic early-onset AD (sEOAD) patient of a 54-year-old Korean man, where a novel APOE Leu159Pro heterozygous mutation was revealed upon Whole Exome Sequence analysis. The proband's CSF showed downregulated levels of Aβ42, with unchanged Tau levels. The mutation is in the Low-Density Lipoprotein Receptor (LDLR) region of the APOE gene, which mediates the clearance of APOE lipoproteins. LDLR works as a high-affinity point for APOE. Studies suggest that APOE-LDLR interplay could have varying effects. The LDLR receptor pathway has been previously suggested as a therapeutic target to treat tauopathy. However, the APOE-LDLR interaction has also shown a significant correlation with memory retention. Leu159Pro could be an interesting mutation that could be responsible for a less damaging pattern of AD by suppressing tau-association neurodegeneration while affecting the patient's memory retention and cognitive performance.

Dual Stimuli-Responsive Multifunctional Silicon Nanocarriers for Specifically Targeting Mitochondria in Human Cancer Cells

Specific targeting, selective stimuli-responsiveness, and controlled release of anticancer agents are requested for high therapeutic efficiency with a minimal adverse effect. Herein, we report the sophisticated synthesis and functionalization of fluorescent mesoporous silicon (FMPSi) nanoparticles decorated with graphene oxide (GO) nanosheets. GO-wrapped FMPSi (FMPSi@GO) was loaded with a cisplatin (Cis) anticancer agent, and Cis-loaded FMPSi@GO (FMPSi-Cis@GO) exhibited the dual stimuli (pH and NIR)-responsiveness of controlled drug release, i.e., the drug release rate was distinctly enhanced at acidic pH 5.5 than at neutral pH 7.0 and further enhanced under NIR irradiation at acidic pH condition. Notably, dequalinium-conjugated FMPSi-Cis@GO (FMPSi-Cis@GO@DQA) demonstrated an excellent specificity for mitochondrial targeting in cancer cells without noticeable toxicity to normal human cells. Our novel silicon nanocarriers demonstrated not only stimuli (pH and NIR)-responsive controlled drug release, but also selective accumulation in the mitochondria of cancer cells and destroying them.

Discriminating Potential Genetic Markers for Complete Response and Non-Complete Response Patients to Neoadjuvant Chemotherapy with Locally Advanced Rectal Cancer

Background: Neoadjuvant chemoradiotherapy (nCRT) prior to surgery is considered standard therapy for locally advanced rectal cancer. Unfortunately, most patients with rectal cancer are resistant to radiotherapy. This might be a genetic cause. The role of certain rectal cancer-causing genes has not been completely elucidated. This study aims to investigate the genes responsible for locally advanced rectal cancer patients not reacting to radiotherapy. Methods: Whole exome sequencing of the DNA samples was performed on the samples. Bioinformatic analysis on the subjects was established. Individual genetic information was screened to identify differently expressed genes that more frequently appeared in non-complete response (NCR) compared to complete response (CR) patients after nCRT. All variations were verified by Sanger sequencing. Results: Genotyping information and pathway analyses of the samples indicated genes such as FLCN, CALML5, and ANTXR1 to be commonly mutated in CR group, whereas genes such as GALNTL14, CNKSR1, ACD, and CUL3 were more commonly mutated in the NCR group. Chi-square test revealed some significant variants (<0.05) such as rs3744124 (FLCN), rs28365986 (ANTXR1), rs10904516 (CALML5), rs3738952 (CUL3), rs13394 and rs2293013 (PIH1D1), rs2274531 (GPA33), rs4963048 (BRSK2), rs17883366 (IL3RA), rs2297575 (PSMD5), rs2288101 (GALNT14), and rs11954652 (DCTN4). Conclusion: Identifying an array of genes that separate NCRs from CRs would lead to finding genetic biomarkers for early detection of rectal cancer patients that are resistant to nCRT. A further investigation to validate the significance of genetic biomarkers to segregate NCRs from CRs should be performed with a larger CRC dataset. Protein expression levels, as well as transcriptomic analysis, would also help us understand the mechanism of how these genes could play a role in preventing radiation therapy to patients. This would be essential to prevent redundant radiation therapy.

COVID-19 Genetic Variants and Their Potential Impact in Vaccine Development

In the two years since the SARS-CoV-2 pandemic started, it has caused over 5 million deaths and 400 million infected cases, and the world continues to be on high alert for COVID-19. Among the variants of interest and concern of SARS-CoV-2, the current Omicron (B.1.1.529) and stealth Omicron (BA.2) raised serious concerns due to rapid rates of infection caused by numerous mutations in the spike protein, which could escape from the antibody-mediated neutralization and increase the risk of reinfections. Hence, this work aims to describe the most relevant mutations in the SARS-CoV-2 spike protein, discuss vaccine against variant of concerns, describe rare adverse events after COVID-19 vaccination, introduce the most available promising COVID-19 vaccine candidates, and provide few perspectives of the future variants.

Multi-Target Approach of Murraya koenigii Leaves in Treating Neurodegenerative Diseases

Neurodegenerative diseases (NDs) mainly affect neurons and gradually lead to a loss of normal motor and cognitive functions. Atypical protein homeostasis-misfolding, aggregations and accumulations, oxidative stress, inflammation, and apoptosis-are common features in most NDs. To date, due to the complex etiology and pathogenesis of NDs, no defined treatment is available. There has been increasing interest in plant extracts as potential alternative medicines as the presence of various active components may exert synergistic and multi-pharmacological effects. Murraya koenigii (Rutaceae) is utilized in Ayurvedic medicine for various ailments. Pharmacological studies evidenced its potential antioxidant, anti-inflammatory, anticancer, hepatoprotective, immunomodulatory, antimicrobial, and neuroprotective activities, among others. In line with our interest in exploring natural agents for the treatment of neurodegenerative diseases, this review presents an overview of literature concerning the mechanisms of action and the safety profile of significant bioactive components present in M. koenigii leaves to support further investigations into their neuroprotective therapeutic potential.

Genetics of Autosomal Recessive Spastic Ataxia of Charlevoix-Saguenay (ARSACS) and Role of Sacsin in Neurodegeneration

Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is an early-onset neurodegenerative disease that was originally discovered in the population from the Charlevoix-Saguenay-Lac-Saint-Jean (CSLSJ) region in Quebec. Although the disease progression of ARSACS may start in early childhood, cases with later onset have also been observed. Spasticity and ataxia could be common phenotypes, and retinal optic nerve hypermyelination is detected in the majority of patients. Other symptoms, such as pes cavus, ataxia and limb deformities, are also frequently observed in affected individuals. More than 200 mutations have been discovered in the SACS gene around the world. Besides French Canadians, SACS genetics have been extensively studied in Tunisia or Japan. Recently, emerging studies discovered SACS mutations in several other countries. SACS mutations could be associated with pathogenicity either in the homozygous or compound heterozygous stages. Sacsin has been confirmed to be involved in chaperon activities, controlling the microtubule balance or cell migration. Additionally, sacsin may also play a crucial role in regulating the mitochondrial functions. Through these mechanisms, it may share common mechanisms with other neurodegenerative diseases. Further studies are needed to define the exact functions of sacsin. This review introduces the genetic mutations discovered in the SACS gene and discusses its pathomechanisms and its possible involvement in other neurodegenerative diseases.

Phytosterols: Potential Metabolic Modulators in Neurodegenerative Diseases

Phytosterols constitute a class of natural products that are an important component of diet and have vast applications in foods, cosmetics, and herbal medicines. With many and diverse isolated structures in nature, they exhibit a broad range of biological and pharmacological activities. Among over 200 types of phytosterols, stigmasterol and β-sitosterol were ubiquitous in many plant species, exhibiting important aspects of activities related to neurodegenerative diseases. Hence, this mini-review presented an overview of the reported studies on selected phytosterols related to neurodegenerative diseases. It covered the major phytosterols based on biosynthetic considerations, including other phytosterols with significant in vitro and in vivo biological activities.

The potential anti-amyloidogenic candidate, SPA1413, for Alzheimer's disease

BACKGROUND AND PURPOSE

Recently, isoflavone derivatives have been shown to have neuroprotective effects against neurological disorders. For instance, genistein attenuated the neuroinflammation and amyloid-β accumulation in Alzheimer's disease animal models, suggesting the potential for use to prevent and treat Alzheimer's disease.

EXPERIMENTAL APPROACH

Here, 50 compounds, including isoflavone derivatives, were constructed and screened for the inhibitory effects on amyloid-β₄₂ fibrilization and oligomerization using the high-throughput screening formats of thioflavin T assay and multimer detection system, respectively. The potential neuroprotective effect of t3-(4-hydroxyphenyl)-2H-chromen-7-ol (SPA1413), also known as dehydroequol, idronoxil or phenoxodiol, was evaluated in cells and in 5xFAD (B6SJL) transgenic mouse, a model of Alzheimer's disease.

KEY RESULTS

SPA1413 had a potent inhibitory action on both amyloid-β fibrilization and oligomerization. In the cellular assay, SPA1413 prevented amyloid-β-induced cytotoxicity and reduced neuroinflammation. Remarkably, the oral administration of SPA1413 ameliorated cognitive impairment, decreased amyloid-β plaques and activated microglia in the brain of 5xFAD (B6SJL) transgenic mouse.

CONCLUSION AND IMPLICATIONS

Our results strongly support the repurposing of SPA1413, which has already received fast-track status from the US Food and Drug Administration (FDA) for cancer treatment, for the treatment of Alzheimer's disease due to its potent anti-amyloidogenic and anti-neuroinflammatory actions.

Mechanistic Aspects of Apiaceae Family Spices in Ameliorating Alzheimer's Disease

Alzheimer's disease (AD) is one of the most prevalent neurodegenerative diseases worldwide. In an effort to search for new strategies for treating AD, natural products have become candidates of choice. Plants are a rich source of bioactive and effective compounds used in treating numerous diseases. Various plant extracts are known to display neuroprotective activities by targeting different pathophysiological pathways in association with the diseases, such as inhibiting enzymes responsible for degrading neurotransmitters, reducing oxidative stress, neuroprotection, inhibiting amyloid plaque formation, and replenishing mitochondrial function. This review presented a comprehensive evaluation of the available scientific literature (in vivo, in vitro, and in silico) on the neuroprotective mechanisms displayed by the extracts/bioactive compounds from spices belonging to the Apiaceae family in ameliorating AD.

Enhanced proliferation of rabbit chondrocytes by using a well circulated nanoshock system

The gold nanorods (GNRs) embedded alginate-chitosan (scaffold), which was designed and fabricated to produce efficient handling of the cell proliferations. Scaffold embedded GNR (SGNR) and NIR (near infrared) irradiations are developing into an interesting medical prognosis tool for rabbit chondrocyte (RC) proliferation. SGNR contained a pattern of uniform pores. Biocompatibility and cellular proliferation achieved by disclosures to NIR irradiations, providing high cell survival. SGNR and NIR irradiations could produce mechanical and biochemical cues for regulating RCs proliferations. To determine the thermal stress, it exposed RCs to 39–42 °C for 0–240 min at the start point of the cell culture cycle. It produced photothermal stress in cellular surrounding (cells located adjacent to and within scaffold) and it deals with the proliferation behavior of RC. All the processes were modeled with experimental criteria and time evolution process. Our system could help the cell proliferation by generating heat for cells. Hence, the present strategy could be implemented for supporting cell therapeutics after transplantation. This implementation would open new design techniques for integrating the interfaces between NIR irradiated and non-irradiated tissues.

Plasma amyloid-β oligomerization assay as a pre-screening test for amyloid status

OBJECTIVE

We assessed the performance of plasma amyloid oligomerization tendency (OAβ) as a marker for abnormal amyloid status. Additionally, we examined long-term storage effects on plasma OAβ.

METHODS

We included 399 subjects regardless of clinical diagnosis from the Amsterdam Dementia Cohort and European Medical Information Framework for AD project (age, 63.8 ± 6.6; 44% female). Amyloid status was determined by visual read on positron emission tomography (PET; nabnormal = 206). Plasma OAβ was measured using the multimer detection system (MDS). Long-term storage effects on MDS-OAβ were assessed using general linear models. Associations between plasma MDS-OAβ and Aβ-PET status were assessed using logistic regression and receiver operating characteristics analyses. Correlations between plasma MDS-OAβ and CSF biomarker levels were evaluated using Pearson correlation analyses.

RESULTS

MDS-OAβ was higher in individuals with abnormal amyloid, and it identified abnormal Aβ-PET with an area under the curve (AUC) of 0.74 (95% CI, 0.67-0.81), especially in samples with a storage duration < 4 years. Combining APOEe4 and age with plasma MDS-OAβ revealed an AUC of 81% for abnormal amyloid PET status (95% CI, 74-87%). Plasma MDS-OAβ correlated negatively with MMSE (r = - 0.29, p < .01) and CSF Aβ42 (r = - 0.20, p < 0.05) and positively with CSF Tau (r = 0.20, p = 0.01).

CONCLUSIONS

Plasma MDS-OAβ combined with APOEe4 and age accurately identifies brain amyloidosis in a large Aβ-confirmed population. Using plasma MDS-OAβ as a screener reduced the costs and number of PET scans needed to screen for amyloidosis, which is relevant for clinical trials. Additionally, plasma MDS-OAβ levels appeared affected by long-term storage duration, which could be of interest for others measuring plasma Aβ biomarkers.

Neuroprotective effects on amyloid-beta induced cytotoxicity of Pandanus clementis Merr

The present study determined the neuroprotective potential of the alcoholic and aqueous extracts of Pandanus clementis Merr. (Pandanaceae) to protect the neuroblastoma SH-SY5Y cells against amyloid-beta _1-42 (Aβ) cytotoxicity. Inhibition of Aβ aggregation was determined by Thioflavin T (ThT) assay, and in vitro neuroprotective cell viability, intracellular reactive oxygen species (ROS), and mitochondrial membrane potential (MMP) were evaluated with human neuroblastoma SH-SY5Y cells insulted with Aβ. Chromatographic separation on the alcoholic extract yielded known phytosterols. Results showed that pretreatment of the SH-SY5Y cells with the P. clementis extracts increased cell viability and MMP, and decreased ROS, suggesting protective effects. Hence, P. clementis extract has promising neuroprotective therapeutic potential.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13205-021-02889-3.

Decreased Exosomal Acetylcholinesterase Activity in the Plasma of Patients With Parkinson's Disease

Exosomes, which are small extracellular vesicles produced from various cell types, contain a variety of molecular constituents, such as proteins, lipids, and RNA. Recently, exosomal biomarkers have been investigated to probe the understanding and diagnosis of neurodegenerative disorders. Previous reports have demonstrated increased exosomal α-synuclein (α-syn) in patients with Parkinson’s disease (PD) in comparison to healthy controls (HC). Interestingly, the cholinergic loss was revealed in the central and peripheral nervous systems in histopathology and molecular neuroimaging. Thereby, we simultaneously examined acetylcholinesterase (AChE) with α-syn as exosomal markers. Exosomes were isolated from the plasma of 34 FP-CIT PET proven patients with PD and 29 HC. Exosomal α-syn and AChE activity were quantified andthe relationship with clinical parameters was analyzed. Remarkably, exosomal AChE activity was significantly decreased in PD compared to HC (P = 0.002). Moreover, exosomal AChE activity in PD revealed a strong negative correlation with disease severity, including H&Y (P = 0.007) and UPDRS part III (P = 0.047) scores. By contrast, no significant difference in exosomal α-syn concentration was observed between groups. These results support the occurrence of cholinergic dysfunction in PD, and they could be implicated with disease progression, especially motor deficits. Exosomal AChE activity with advanced exosome isolation techniques may be a reliable biomarker for the early diagnosis and prognosis of PD.

Blood Amyloid-β Oligomerization as a Biomarker of Alzheimer's Disease: A Blinded Validation Study

BACKGROUND

Oligomeric amyloid-β (Aβ) is one of the major contributors to the pathomechanism of Alzheimer's disease (AD); Aβ oligomerization in plasma can be measured using a Multimer Detection System-Oligomeric Aβ (MDS-OAβ) after incubation with spiked synthetic Aβ.

OBJECTIVE

We evaluated the clinical sensitivity and specificity of the MDS-OAβ values for prediction of AD.

METHODS

The MDS-OAβ values measured using inBlood™ OAβ test in heparin-treated plasma samples from 52 AD patients in comparison with 52 community-based subjects with normal cognition (NC). The inclusion criterion was proposed by the NINCDS-ADRDA and additionally required at least 6 months of follow-up from the initial clinical diagnosis in the course of AD.

RESULTS

The MDS-OAβ values were 1.43±0.30 ng/ml in AD and 0.45±0.19 (p < 0.001) in NC, respectively. Using a cut-off value of 0.78 ng/ml, the results revealed 100% sensitivity and 92.31% specificity.

CONCLUSION

MDS-OAβ to measure plasma Aβ oligomerization is a valuable blood-based biomarker for clinical diagnosis of AD, with high sensitivity and specificity.

Plasma Amyloid-β Oligomerization Tendency Predicts Amyloid PET Positivity

Purpose

Among other emerging amyloid-targeting blood-based biomarkers, Multimer Detection System-Oligomeric Amyloid-β (MDS-OAβ) measures dynamic changes in concentration of oligomeric amyloid-β (OAβ), which is considered the main pathogenic culprit of Alzheimer’s disease (AD), in plasma after spiking with synthetic amyloid-β (Aβ). We aimed to investigate the predictability of MDS-OAβ on amyloid positron emission tomography (PET) positivity.

Patients and Methods

A total of 96 subjects who visited Seoul National University Bundang Hospital for medical check-up complaining of cognitive decline and had undergone extensive medical assessment were recruited. Amyloid statuses were dichotomized into positive or negative based on visual assessment of amyloid PET. Plasma OAβ concentration was measured by MDS-OAβ. In the previous validation study, 0.78ng/mL was established as the cut-off value and the plasma OAβ concentration higher than or equal to the cut-off value was defined as MDS-OAβ positive.

Results

MDS-OAβ positivity could discriminate amyloid PET positivity with the AUC value of 0.855 (95% CI 0.776–0.933). Adding MDS-OAβ positivity to prediction models including age, MMSE score, and APOE ε4 status improved performance up to the AUC value of 0.926 (95% CI 0.871–0.980).

Conclusion

The Aβ oligomerization tendency in plasma could predict amyloid PET positivity with high performance, and, when it is combined with age, MMSE score, and APOE ε4 status, predictability was improved substantially. This suggests the potential of MDS-OAβ as a useful initial stage test in the clinical and research fields of AD.

Diaportheone A Analogues Instigate a Neuroprotective Effect by Protecting Neuroblastoma SH-SY5Y Cells from Oxidative Stress

Alzheimer's disease (AD) remains an incurable neurodegenerative illness. Oxidative stress resulting in the formation of reactive oxygen species (ROS) and the abnormal deposition of amyloid-beta (Aβ) are the major pathological hallmarks associated with AD. In search for small molecules targeting multiple pathways of AD and of no known molecular targets, the neuroprotective effects of the synthetic chromones diaportheone A1 and diaportheone A2, analogues of the natural product diaportheone A, were investigated. Chromones are heterocyclic compounds bearing the benzoannelated γ-pyrone moiety and were regarded as an important class of organic molecules due to their diverse pharmacological activities. The influence of the compounds on the inhibition of Aβ aggregation was determined by Thioflavin T (ThT) assay, and the cell viability, ROS, and mitochondrial membrane potential were evaluated with human neuroblastoma SH-SY5Y cells. Results showed that both compounds inhibited the Aβ aggregation at 80.41% and 73.68% for diaportheone A1 and diaportheone A2, respectively. Increased cell viabilities were observed from the protection by both compounds using Aβ- or H₂O₂-induced SH-SY5Y cells. Both compounds also reduced the intracellular ROS level in Aβ- or H₂O₂-induced SH-SY5Y cells at 10 and 20 μM concentrations, and increased the mitochondrial membrane potentials in Aβ-induced SH-SY5Y cells at 20 μM concentration. Molecular docking experiments using the Aβ protein models 2MXU and 2BEG also indicated a good agreement with the experimental data. The results demonstrated for the first time the oxidative stress effects associated with the chromones diaportheone A1 and diaportheone A2 as potential neuroprotective therapeutic agents against AD.

Cancer Cell Detection on the Surface of Top-Gated Monolayer Graphene via Raman Spectroscopy

A label-free biosensor is described based on the Raman spectroscopic signatures of monolayer graphene, which are modified in the compartment of cancer cells because of electron-phonon coupling in monolayer graphene. Specifically, the Raman spectra of electrostatically gated monolayer graphene on SiO₂/Si substrates, in the voltage range from 0 to 5 V, were studied in the absence and the presence of cancer cells. Density functional theory simulations afforded a correlation between cancer cells and the observed Raman spectra, through the regulation of the intensities of the G and 2D Raman vibrational modes with applied voltage. The C-H and N-H bonds of phenylalanine enabled the detection of this biosensing activity. Significantly, this detection can be carried out even in the absence of cancer cell-culturing steps.

SARS-CoV-2 (COVID-19): Beginning to Understand a New Virus

Within the last two decades, several members of the Coronaviridae family demonstrated epidemic potential. In late 2019, an unnamed genetic relative, later named SARS-CoV-2 (COVID-19), erupted in the highly populous neighborhoods of Wuhan, China. Unchecked, COVID-19 spread rapidly among interconnected communities and related households before containment measures could be enacted. At present, the mortality rate of COVID-19 infection worldwide is 6.6%. In order to mitigate the number of infections, restrictions or recommendations on the number of people that can gather in a given area have been employed by governments worldwide. For governments to confidently lift these restrictions as well as counter a potential secondary wave of infections, alternative medications and diagnostic strategies against COVID-19 are urgently required. This review has focused on these issues.

Multimodal Mesoporous Silica Nanocarriers for Dual Stimuli-Responsive Drug Release and Excellent Photothermal Ablation of Cancer Cells

Background

Core-shell types of mesoporous silica nanoparticles (MSNs) with multimodal functionalities were developed for bio-imaging, controlled drug release associated with external pH, and near-infrared radiation (NIR) stimuli, and targeted and effective chemo-photothermal therapeutics.

Materials and Methods

We synthesized and developed a core-shell type of mesoporous silica nanocarriers for fluorescent imaging, stimuli-responsive drug release, magnetic separation, antibody targeting, and chemo-photothermal therapeutics. Also, the biocompatibility, cellular uptake, cytotoxicity, and photothermal therapy on these FS3-based nanocarriers were systematically investigated.

Results

Magnetic mesoporous silica nanoparticles was prepared by coating a Fe₃O₄ core with a mesoporous silica shell, followed by grafting with fluorescent conjugates, so-called FS3. The resulting FM3 was preloaded with therapeutic cisplatin and coated with polydopamine layer, so-called FS3P/C. Eventually, graphene oxide-wrapped FS3P/C (FS3P-G/C) exhibited high sensitivity in the dual stimuli (pH, NIR)-responsive controlled release behavior. On the other hand, Au NPs-coated FS3P/C (FS3P-A/C) exhibited more stable release behavior, irrespective of pH changes, and exhibited much more enhanced release rate under the same NIR irradiation. Notably, FS3P-A/C showed strong NIR absorption, enabling photothermal destruction of HeLa cells by its chemo-photothermal therapeutic effects under NIR irradiation (808 nm, 1.5 W/cm²). The selective uptake of FS3-based nanocarriers was confirmed in cancer cell lines including HeLa (American Type Culture Collection - ATCC) and SHSY5Y (ATCC 2266) by the images obtained from confocal laser scanning microscopy, flow cytometry, and transmission electron microscopy instruments. Cisplatin-free FS3-based nanocarriers revealed good cellular uptake and low cytotoxicity against cancerous HeLa and SH-SY5Y cells, but showed no obvious toxicity to normal HEK293 (ATCC 1573) cell.

Conclusion

Along with the facile synthesis of FS3-based nanocarriers, the integration of all these strategies into one single unit will be a prospective candidate for biomedical applications, especially in chemo-photothermal therapeutics, targeted delivery, and stimuli-responsive controlled drug release against multiple cancer cell types.

Neuroprotective effects of vomifoliol, isolated from Tarenna obtusifolia Merr. (Rubiaceae), against amyloid-beta 1-42-treated neuroblastoma SH-SY5Y cells

Phytochemical investigation on the leaves of Tarenna obtusifolia Merr. (Rubiaceae) led to the isolation and identification of vomifoliol (1), p-coumaric acid (2), and stigmasterol (3) based on spectroscopic analyses and comparison with the literature data. Compound 1 moderately inhibited the aggregation of amyloid-beta (Aβ_1-42) using the ThT assay (55.71% at 50 μM) and exhibited neuroprotective effects against amyloid-beta (Aβ_1-42)-induced cytotoxicity in neuroblastoma SH-SY5Y cells at 20 μM concentration. This is the first phytochemical study on T. obtusifolia and the first report on the Aβ aggregation activity and neuroprotective potential of vomifoliol (1).

CSF total tau/α-synuclein ratio improved the diagnostic performance for Alzheimer's disease as an indicator of tau phosphorylation

Background

Recently, several studies suggested potential involvements of α-synuclein in Alzheimer’s disease (AD) pathophysiology. Higher concentrations of α-synuclein were reported in cerebrospinal fluid (CSF) of AD patients with a positive correlation towards CSF tau, indicating its possible role in AD. We analyzed the CSF biomarkers to verify whether α-synuclein could be an additional supported biomarker in AD diagnosis.

Methods

In this cross-sectional study, CSF samples of 71 early-onset AD, 34 late-onset AD, 11 mild cognitive impairment, 17 subjective cognitive decline, 45 Parkinson’s disease, and 32 healthy control (HC) were collected. CSF amyloid-β1-42 (A), total tau (N), and phosphorylated tau181 (T) were measured by commercial ELISA kits, and in-house ELISA kit was developed to quantify α-synuclein. The cognitive assessments and amyloid-PET imaging were also performed.

Results

CSF α-synuclein manifested a tendency to increase in AD and to decreased in Parkinson’s disease compared to HC. The equilibrium states of total tau and α-synuclein concentrations were changed significantly in AD, and the ratio of total tau/α-synuclein (N/αS) was dramatically increased in AD than HC. Remarkably, N/αS revealed a strong positive correlation with tau phosphorylation rate. Also, the combination of N/αS with amyloid-β1-42/phosphorylated tau181 ratio had the best diagnosis performance (AUC = 0.956, sensitivity = 96%, specificity = 87%). In concordance analysis, N/αS showed the higher diagnostic agreement with amyloid-β1-42 and amyloid-PET. Analysis of biomarker profiling with N/αS had distinctive characteristics and clustering of each group. Especially, among the group of suspected non-Alzheimer’s disease pathophysiology, all A−T+N+ patients with N/αS+ were reintegrated into AD.

Conclusions

The high correlation of α-synuclein with tau and the elevated N/αS in AD supported the involvement of α-synuclein in AD pathophysiology. Importantly, N/αS improved the diagnostic performance, confirming the needs of incorporating α-synuclein as a biomarker for neurodegenerative disorders. The incorporation of a biomarker group [N/αS] could contribute to provide better understanding and diagnosis of neurodegenerative disorders.

Additional diagnostic testing of the 2019 novel coronavirus (SARS-CoV-2)

Purpose of review

Within the last two decades several members of the Coronaviridae family namely Severe Respiratory Syndrome (SARS-CoV) and Middle East Respiratory Syndrome (MERS-CoV) have demonstrated epidemic potential. In late, 2019 an unnamed genetic relative, later named SARS-CoV-2 realized its potential in the highly populous neighborhoods of Wuhan, China. Unchecked, the virus rapidly spread among interconnected communities and related households before containment measures could be in acted. “Appropriate” diagnostic testing in response to the SARS-CoV-2 outbreak should be urgently considered. This perspective review gives particular attention to the potential diagnostic testing of the virus in semen and seminal fluids due to its high levels of angiotensin converting enzyme 2 (ACE2) precursor.

Recent findings

As many infectious viruses are stable in semen and have transmitted the respective diseases, the presence of SARS-CoV-2 should be tested in semen to assess their stabilities and half-life. As in case of Ebola virus, it was present in semen for longer period in a carrier man without any symptom. Additional hypothesis is that since ACE2 could serve as a mediator for the endocytosis of the previously SARS coronavirus, SARS-CoV-2 may enter the cells through similar mechanism. From the protein expression atlas, high levels of ACE2 precursor were found in intestines and testis. Hence, the testis and seminal fluids could be the host cell and/or reservoir. The results could be used as a suggestive guideline for the sexual activities after the discharge or declaration of disease free.

The influence of Aβ-dependent and independent pathways on TDP-43 proteinopathy in Alzheimer's disease: a possible connection to LATE-NC

Alzheimer's disease (AD) is a progressive neurodegenerative disorder that results from the accumulation of plaques by cleaved Aβ₄₂ peptides as well as neurofibrillary tangles of tau proteins. This accumulation triggers a complex cascade of cytotoxic, neuroinflammatory, and oxidative stresses that lead to neuronal death throughout the progression of the disease. Much of research in AD focused on the 2 pathologic proteins. Interestingly, another form of dementia with similar clinical manifestations of AD, but preferentially affected much older individuals, was termed as limbic-predominant age-related transactive response DNA-binding protein 43 (TDP-43) encephalopathy (LATE) and involved the cytotoxic intraneuronal deposition of phosphorylated TDP-43. TDP-43 proteinopathy was also found to be involved in AD pathology leading to the possibility that AD and LATE may share a common upstream etiology. This paper discusses the roles molecular pathways known in AD may have on influencing TDP-43 proteinopathy and the development of AD, LATE, or the 2 being comorbid with each other.

Neuroblastoma SH-SY5Y cytotoxicity, anti-amyloidogenic activity and cyclooxygenase inhibition of Lasianthus trichophlebus (Rubiaceae)

The anti-amyloidogenic potential and cyclooxygenase anti-inflammatory activity of Lasianthus trichophlebus extracts were evaluated. The MeOH extract (LTM) and chloroform extract (LTC) exhibited significant cytotoxic inhibition against the neuroblastoma SH-SY5Y cell with an IC₅₀ of 17.52 μg/mL and 12.28 μg/mL, respectively. Thioflavin T assay indicated the LTC extract inhibition (70.56% at 50 μg/mL) to be statistically comparable (p < 0.05) to the positive control. Cyclooxygenase inhibition against COX-1 and COX-2 enzymes gave IC₅₀ values for the LTM extract to be 18.20 and 29.60 µg/mL, respectively; while, the LTC extract showed 4.11 and 2.78 µg/mL, respectively. LC-MS of the LTM extract identified 22 putative compounds, which may prove to be pharmacologically relevant. This study has provided potential insights into the utilization of L. trichophlebus to develop safer plant-based agents for anti-inflammatory or neurodegenerative diseases.

Pathogenic PSEN1 Glu184Gly Mutation in a Family from Thailand with Probable Autosomal Dominant Early Onset Alzheimer's Disease

A pathogenic mutation in PSEN1 p.Glu184Gly was discovered in a Thai family with early onset Alzheimer's disease (EOAD) as the first case in Asia. Proband patient presented memory impairment and anxiety at the age of 41 years. Family history was positive, since several family members were also diagnosed with dementia (father and grandfather). MRI in the patient revealed global cortical atrophy without specific lesions or lacuna infarctions. Extensive genetic profiling for 50 neurodegenerative disease related genes was performed by next generation sequencing (NGS) on the patient. PSEN1 Glu184Gly was previously reported in French families with frontal variant Alzheimer's disease (AD). Interestingly, this mutation is located near the splicing site and could possibly result in abnormal cleavage of PSEN1 transcript. Furthermore, 3D models from protein structural predictions revealed significant structural changes, since glycine may result in increased flexibility of TM-III helix. Inter/intra-helical interactions could also be altered. In the future, functional studies should be performed to verify the probable role PSEN1 Glu184Gly in amyloid beta processing and pathogenicity.

In vivo COX-2 modulation and metabolite profiling of Pandanus tectorius leaves extracts

The Pandanus tectorius methanolic (PTM) and P. tectorius aqueous (PTA) extracts were investigated for their potential in vivo anti-inflammatory activity using carrageenan-induced rat paw edema. Parameters including paw thickness measurement, histopathological, and immunohistochemical cyclooxygenase (COX)-2 expression analyses were measured and analyzed. PTA at 500 mg/kg significantly reduced inflammation after induction of carrageenan (Carr), with mean paw thickness change of 0.110 ± 0.024 mm at sixth hour post-induction and histopathological mean inflammatory grade of 1.80 ± 0.20. The reduced immunohistochemical COX-2 expression using PTA at 500 mg/kg was determined with mean final 3,3'-diaminobenzidine (DAB) intensity of 63.70 ± 2.08. The profiling of metabolites by liquid chromatography-mass spectrometry (LC-MS) revealed presence of ethyl caffeate and dihydroconiferyl alcohol as putative secondary metabolites of PTA which were the major peaks and have been reported to possess anti-inflammatory activities. This research has provided scientific insights of utilizing P. tectorius as a potential anti-inflammatory agent containing secondary metabolites which may be pharmacologically relevant.

BMD42-2910, a Novel Benzoxazole Derivative, Shows a Potent Anti-prion Activity and Prolongs the Mean Survival in an Animal Model of Prion Disease

Prion diseases are a group of neurodegenerative and fatal central nervous system disorders. The pathogenic mechanism involves the conversion of cellular prion protein (PrP^C) to an altered scrapie isoform (PrP^Sc), which accumulates in amyloid deposits in the brain. However, no therapeutic drugs have demonstrated efficacy in clinical trials. We previously reported that BMD42-29, a synthetic compound discovered in silico, is a novel anti-prion compound that inhibits the conversion of PrP^C to protease K (PK)-resistant PrP^Sc fragments (PrP^res). In the present study, 14 derivatives of BMD42-29 were obtained from BMD42-29 by modifying in the side chain by in silico feedback, with the aim to determine whether they improve anti-prion activity. These derivatives were assessed in a PrP^Sc-infected cell model and some derivatives were further tested using real time-quaking induced conversion (RT-QuIC). Among them, BMD42-2910 showed high anti-prion activity at low concentrations in vitro and also no toxic effects in a mouse model. Interestingly, abundant PrP^res was reduced in brains of mice infected with prion strain when treated with BMD42-2910, and the mice survived longer than control mice and even that treated with BMD42-29. Finally, high binding affinity was predicted in the virtual binding sites (Asn159, Gln 160, Lys194, and Glu196) when PrP^C was combined with BMD-42-2910. Our findings showed that BMD42-2910 sufficiently reduces PrP^res generation in vitro and in vivo and may be a promising novel anti-prion compound.