Advances in amyloid beta oligomer detection applications in Alzheimer's disease

Covalent organic framework-based ratiometric electrochemical sensing platform for ultrasensitive determination of amyloid-β 42 oligomer

Accurate and sensitive detection of amyloid-β 42 oligomer (Aβ42O) is of great significance for early diagnosis of Alzheimer's disease (AD). Herein, a signal on-off ratiometric electrochemical immunosensor was developed for highly selective and quantitative determination of Aβ42O by using novel covalent organic frameworks (COFs) composites as the sensing platform. This immunosensor produced two independent electrochemical signals from the [Fe(CN)6]3-/4- and methylene blue (MB) probes at different potentials based on the electrocatalytic activity of gold nanoparticle-functionalized porphyrinyl COFs nanocomposites toward [Fe(CN)6]3-/4- and the signal probe of MB encapsulated in the aptamer-modified alkynyl COFs. Because the two signals of [Fe(CN)6]3-/4- and MB changed in opposite directions, a signal on-off mode was generated which can correct the results by introducing a reference signal and effectively eliminate background interference. Under optimal experimental conditions, the current ratio (IMB/I[Fe(CN)6]3-/4-) was well linearly related to the logarithmic value of Aβ42O concentrations in the range of 10 pM to 1 μM, and the detection limit was 5.1 pM (S/N = 3). Additionally, the immunosensor exhibited satisfactory performance in case of real cerebrospinal fluid samples. The designed ratiometric electrochemical immunosensor provides a valuable route for early diagnosis of AD and our results also pave the way for designing of sensing platforms using COF-based nanomaterials and extending their functions and applications to bioanalysis.

Gold Nanoparticle-Decorated Catalytic Micromotor-Based Aptassay for Rapid Electrochemical Label-Free Amyloid-β42 Oligomer Determination in Clinical Samples from Alzheimer's Patients

Micromotor (MM) technology offers a valuable and smart on-the-move biosensing microscale approach in clinical settings where sample availability is scarce in the case of Alzheimer's disease (AD). Soluble amyloid-β protein oligomers (AβO) (mainly AβO42) that circulate in biological fluids have been recognized as a molecular biomarker and therapeutic target of AD due to their high toxicity, and they are correlated much more strongly with AD compared to the insoluble Aβ monomers. A graphene oxide (GO)-gold nanoparticles (AuNPs)/nickel (Ni)/platinum nanoparticles (PtNPs) micromotors (MMGO-AuNPs)-based electrochemical label-free aptassay is proposed for sensitive, accurate, and rapid determination of AβO42 in complex clinical samples such as brain tissue, cerebrospinal fluid (CSF), and plasma from AD patients. An approach that implies the in situ formation of AuNPs on the GO external layer of tubular MM in only one step during MM electrosynthesis was performed (MMGO-AuNPs). The AβO42 specific thiolated-aptamer (AptAβO42) was immobilized in the MMGO-AuNPs via Au-S interaction, allowing for the selective recognition of the AβO42 (MMGO-AuNPs-AptAβO42-AβO42). AuNPs were smartly used not only to covalently bind a specific thiolated-aptamer for the design of a label-free electrochemical aptassay but also to improve the final MM propulsion performance due to their catalytic activity (approximately 2.0× speed). This on-the-move bioplatform provided a fast (5 min), selective, precise (RSD < 8%), and accurate quantification of AβO42 (recoveries 94-102%) with excellent sensitivity (LOD = 0.10 pg mL-1) and wide linear range (0.5-500 pg mL-1) in ultralow volumes of the clinical sample of AD patients (5 μL), without any dilution. Remarkably, our MM-based bioplatform demonstrated the competitiveness for the determination of AβO42 in the target samples against the dot blot analysis, which requires more than 14 h to provide qualitative results only. It is also important to highlight its applicability to the potential analysis of liquid biopsies as plasma and CSF samples, improving the reliability of the diagnosis given the heterogeneity and temporal complexity of neurodegenerative diseases. The excellent results obtained demonstrate the analytical potency of our approach as a future tool for clinical/POCT (Point-of-care testing) routine scenarios.

Characterizing amyloid protein conformation with a multi-resonant metasurface based biosensor in the infrared window

Misfolding of amyloid protein will cause neurodegeneration and trigger conformational disease. The lack of an effective detection approach is a brake on unveiling the mechanism of protein misfolding. We theoretically proposed a novel metasurface-based biosensor for characterizing the protein's conformation. The coupling complementary split ring resonator (cSRR) was engineered to manipulate incident waves in the near-infrared (NIR) and mid-infrared (MIR) windows at the same sensing surface. The cSRRs had the advantages of intensifying the electric field and sharpening the resonance profile, resulting in a highly qualified biosensing performance. In the NIR window, the biolayer's refractive index and thickness change were detected by the dual-wavelength, which resolved into an optogeometrical parameter of the amyloid biolayer. In the MIR window, the resonant wave specifically triggered the rotation-vibration transition of amyloid protein molecules with different conformations, which was shown as the unique Amide I and II bands in the fingerprint spectrum. Thus, our proposed biosensor presented sensitive detection of biolayer and specific identification of constituent molecules. It is helpful to interpret the protein's misfolding behavior on the molecular level by associating the biolayer's structure and the constituent molecule's conformational change.

Recent Developments of Hybrid Fluorescence Techniques: Advances in Amyloid Detection Methods

Amyloid fibrils are formed from various pathological proteins. Monitoring their aggregation process is necessary for early detection and treatment. Among the available detection techniques, fluorescence is simple, intuitive, and convenient due to its sensitive and selective mode of detection. It has certain disadvantages like poor photothermal stability and detection state limitation. Research has focused on minimising the limitation by developing hybrid fluorescence techniques. This review focuses on the two ways fluorescence (intrinsic and extrinsic) has been used to monitor amyloid fibrils. In intrinsic/label free fluorescence: i) The fluorescence emission through aromatic amino acid residues like phenylalanine (F), tyrosine (Y) and tryptophan (W) is present in amyloidogenic peptides/protein sequence. And ii) The structural changes from alpha helix to cross-β-sheet structures during amyloid formation contribute to the fluorescence emission. The second method focuses on the use of extrinsic fluorophores to monitor amyloid fibrils i) organic dyes/small molecules, ii) fluorescent tagged proteins, iii) nanoparticles, iv) metal complexes and v) conjugated polymers. All these fluorophores have their own limitations. Developing them into hybrid fluorescence techniques and converting it into biosensors can contribute to early detection of disease.

Alzheimer's Disease Biomarker Detection Using Field Effect Transistor-Based Biosensor

Alzheimer's disease (AD) is closely related to neurodegeneration, leading to dementia and cognitive impairment, especially in people aged > 65 years old. The detection of biomarkers plays a pivotal role in the diagnosis and treatment of AD, particularly at the onset stage. Field-effect transistor (FET)-based sensors are emerging devices that have drawn considerable attention due to their crucial ability to recognize various biomarkers at ultra-low concentrations. Thus, FET is broadly manipulated for AD biomarker detection. In this review, an overview of typical FET features and their operational mechanisms is described in detail. In addition, a summary of AD biomarker detection and the applicability of FET biosensors in this research field are outlined and discussed. Furthermore, the trends and future prospects of FET devices in AD diagnostic applications are also discussed.

Two-Photon Fluorescent Probes for Amyloid-β Plaques Imaging In Vivo

Amyloid-β (Aβ) peptide deposition, hyperphosphorylated tau proteins, reactive astrocytes, high levels of metal ions, and upregulated monoamine oxidases are considered to be the primary pathological markers of Alzheimer's disease (AD). Among them, Aβ peptide deposition or Aβ plaques, is regarded as the initial factor in the pathogenesis of AD and a critical pathological hallmark in AD. This review highlights recently Aβ-specific fluorescent probes for two-photon imaging of Aβ plaques in vivo. It includes the synthesis and detection mechanism of probes, as well as their application to two-photon imaging of Aβ plaques in vivo.

SAM-Support-Based Electrochemical Sensor for Aβ Biomarker Detection of Alzheimer's Disease

Alzheimer's disease has taken the spotlight as a neurodegenerative disease which has caused crucial issues to both society and the economy. Specifically, aging populations in developed countries face an increasingly serious problem due to the increasing budget for patient care and an inadequate labor force, and therefore a solution is urgently needed. Recently, diverse techniques for the detection of Alzheimer's biomarkers have been researched and developed to support early diagnosis and treatment. Among them, electrochemical biosensors and electrode modification proved their effectiveness in the detection of the Aβ biomarker at appropriately low concentrations for practice and point-of-care application. This review discusses the production and detection ability of amyloid beta, an Alzheimer's biomarker, by electrochemical biosensors with SAM support for antibody conjugation. In addition, future perspectives on SAM for the improvement of electrochemical biosensors are also proposed and discussed.

Evolution of Detecting Early Onset of Alzheimer's Disease: From Neuroimaging to Optical Immunoassays

Alzheimer's disease (AD) is a pathological disorder defined by the symptoms of memory loss and deterioration of cognitive abilities over time. Although the etiology is complex, it is mainly associated with the accumulation of toxic amyloid-β peptide (Aβ) aggregates and tau protein-induced neurofibrillary tangles (NFTs). Even now, creating non-invasive, sensitive, specific, and cost-effective diagnostic methods for AD remains challenging. Over the past few decades, polymers, and nanomaterials (e.g., nanodiamonds, nanogold, quantum dots) have become attractive and practical tools in nanomedicine for diagnosis and treatment. This review focuses on current developments in sensing methods such as enzyme-linked immunosorbent assay (ELISA) and surface-enhanced Raman scattering (SERS) to boost the sensitivity in detecting related biomarkers for AD. In addition, optical analysis platforms such as ELISA and SERS have found increasing popularity among researchers due to their excellent sensitivity and specificity, which may go as low as the femtomolar range. While ELISA offers easy technological usage and high throughput, SERS has the advantages of improved mobility, simple electrical equipment integration, and lower cost. Both portable optical sensing techniques are highly superior in terms of sensitivity, specificity, human application, and practicality, enabling the early identification of AD biomarkers.

Protein conformation characterization via a silicon resonator-based optical sensor based on the combination of wavelength interrogation and dual polarization detection

Protein conformational abnormality causes cell malfunction. Conformational change of amyloid protein causes neuron malfunction, which renders "protein conformational disease" Alzheimer's disease. Dual polarization interferometry enables to provide one-dimensional structure of a protein biolayer via deconvolution of interference patterns, which in turn is interpreted as the protein molecule conformation. However, it is still challenging to avoid interference patterns becoming faint and obscure sometimes. Resonance wavelength response to the biolayer structure can achieve a very low detection limit due to inherent high Q factor of an optical resonator. Here, we introduce the concept of combining dual polarization detection with wavelength interrogation via a simple and compact resonator-based optical biosensor. Biolayer were probed by the wave of dual polarization and its opto-geometrical parameters were resolved into resonance wavelength shift. Because protein molecule with distinct conformation produced a biolayer with unique thickness and mass density. Amyloid proteins in monomeric and dimeric morphology were respectively characterized. This concept enables protein conformation characterization in an easy and direct paradigm and provides a desirable sensing performance due to sensitive resonance response in the form of the sharp resonance profile occurring in a nonoverlapping spectrum.

Electrochemical Immunosensor for Early Detection of β-Amyloid Alzheimer's Disease Biomarker Based on Aligned Carbon Nanotubes Gold Nanocomposites

Beta-amyloid (βA) peptides accompanying the physiological change in brain induce Alzheimer's disease. In this work, a highly sensitive electrochemical (EC) immunosensor platform has been developed for the quantitative detection of βA peptides, using the gold nanoparticle functionalized chitosan-aligned carbon nanotube (CS-aCNT-Au) nanocomposites on glassy carbon electrodes (GCE). The immunosensor has been fabricated by immobilization of the anti-βA antibody upon CS-aCNT-Au/GCE. In the CS-aCNT nanocomposite, CS has high biocompatibility. Hydroxy and amine functionalities favor the antibody immobilization and prevent the leaching of nanocomposites of the modified electrode due to the adhesive environment. Moreover, aCNT offers high conductivity, stability, and a large surface area (the calculated effective surface area of the CS-aCNT/GCE is 8.594 × 10^-2 cm²). However, the incorporation of AuNPs further enhances the conductivity of the CS-aCNT-Au nanocomposite based on differential pulse voltammetry (DPV) results, and also improves the effective surface area (9.735 × 10^-2 cm²). The surface morphology and electrochemical studies of the nanocomposite, as well as its modifications by the anti-βA antibody and BSA, were carried out through field emission scanning electron microscope (FESEM), cyclic voltammetry (CV), and DPV. The quantitative immunosensing of the βA in phosphate-buffered saline (PBS) solution is accomplished via DPV, which reveals that the immunosensor has a high sensitivity of 157.60 µA pg^-1 mL cm^-2 and a broad detection range of 10.0 pg mL^-1-100.0 µg mL^-1, with a limit of detection (LOD) of 0.87 pg mL^-1. Subsequently, we detected the spiked βA in diluted serum with a linear detection range of 10.0 pg mL^-1-1.0 ng mL^-1 and LOD of 0.95 pg mL^-1. Moreover, a selectivity study exhibited a high affinity of immunosensors towards βA. Thus, we propose that this highly efficient immunosensor can potentially be applied for the point-of-care (POC) sensing of βA in clinical samples.

Plasma amyloid-beta oligomer is related to subjective cognitive decline and brain amyloid status

Background

Subjective cognitive decline (SCD) is a target for Alzheimer’s disease prediction. Plasma amyloid-beta oligomer (AβO), the pathogenic form of Aβ in blood, has recently been proposed as a novel blood-based biomarker of AD prediction by representing brain Aβ deposition. The relationship between plasma AβO, brain Aβ deposition, and SCD in individuals with normal objective cognition has not been investigated.

Methods

In this cross-sectional study, we analyzed 126 participants with normal objective cognition. More SCD symptoms were expressed as higher scores of the Subjective Cognitive Decline Questionnaire (SCDQ) and Memory Age-associated Complaint Questionnaire (MACQ). The plasma AβO level of each participant was measured twice for validation and expressed as a concentration (ng/mL) and a ratio relative to the mean value of two internal standards. Brain Aβ deposition was assessed by [¹⁸F] flutemetamol positron emission tomography (PET) and expressed as standard uptake value ratio (SUVR). Associations of SCDQ and MACQ with plasma AβO levels or SUVR were analyzed in multiple linear regression models. The association between plasma AβO level and flutemetamol PET positivity was assessed in logistic regression and receiver operative characteristic analyses.

Results

Overall, participants were 73.3 years old with female predominance (69.0%). After adjustment for confounders, high SCDQ and MACQ scores were associated with the high plasma AβO levels as both concentrations and ratios (ratios: standardized coefficient = 0.246 and p = 0.023 for SCDQ, standardized coefficient = 0.209 and p = 0.029 for MACQ; concentrations: standardized coefficient = 0.257 and p = 0.015 for SCDQ, standardized coefficient = 0.217 and p = 0.021 for MACQ). In contrast, SCDQ and MACQ were not significantly associated with SUVRs (p = 0.134 for SCDQ, p = 0.079 for MACQ). High plasma AβO levels were associated with flutemetamol PET (+) with an area under the curve of 0.694 (ratio) or 0.662 (concentration). Combined with APOE e4, plasma AβO presented area under the curves of 0.789 (ratio) and 0.783 (concentration).

Conclusions

Our findings indicate that the high plasma AβO level could serve as a potential surrogate biomarker of severe SCD and the presence of brain Aβ deposition in individuals with normal objective cognition.

Comparative Study of the Solid-Liquid Interfacial Adsorption of Proteins in Their Native and Amyloid Forms

The adhesive properties of amyloid fibers are thought to play a crucial role in various negative and positive aggregation processes, the study of which might help in their understanding and control. Amyloids have been prepared from two proteins, lysozyme and β-lactoglobulin, as well as an Exendin-4 derivative miniprotein (E5). Thermal treatment was applied to form amyloids and their structure was verified by thioflavin T (ThT), 8-Anilino-1-naphthalenesulfonic acid (ANS) dye tests and electronic circular dichroism spectroscopy (ECD). Adsorption properties of the native and amyloid forms of the three proteins were investigated and compared using the mass-sensitive quartz crystal microbalance (QCM) technique. Due to the possible electrostatic and hydrophobic interactions, similar adsorbed amounts were found for the native or amyloid forms, while the structures of the adsorbed layers differed significantly. Native proteins formed smooth and dense adsorption layers. On the contrary, a viscoelastic, highly loose layer was formed in the presence of the amyloid forms, shown by increased motional resistance values determined by the QCM technique and also indicated by atomic force microscopy (AFM) and wettability measurements. The elongated structure and increased hydrophobicity of amyloids might contribute to this kind of aggregation.

Electrocatalysis of Copper Sulfide Nanoparticle-Engineered Covalent Organic Frameworks for Ratiometric Electrochemical Detection of Amyloid-β Oligomer

Amyloid-β oligomer (AβO) is widely regarded as a reliable biomarker for the early diagnosis of Alzheimer's disease (AD). In this study, a signal on-off ratiometric electrochemical immunosensor has been developed for ultrasensitive detection of AβO. To achieve the dual-signal ratiometric strategy, ultrasmall copper sulfide nanoparticle-engineered covalent organic framework hybrid nanocomposites (CuS@COFs) were utilized as excellent electrocatalysts toward hydroquinone (HQ) oxidation to produce detectable signals. Meanwhile, electroactive thionine (Thi) and Aβ antibody-modified gold nanoparticles (Thi-AuNPs-Ab bioconjugates) were designed as another electrochemical indicator. Based on these two signals, an ultrasensitive sandwich-like electrochemical immunosensor was established for AβO detection. The introduction of AβO resulted in a remarkable decline in the electrochemical signal of HQ but an increase in the signal of Thi. Under optimum conditions, the ratios between the double signals (I_Thi/I_HQ) showed a proportional linear relationship with the AβO concentration (1 pM-1 μM) with a low detection limit of 0.4 pM (S/N = 3), and the biosensor was able to determine the content of AβO in real cerebrospinal fluid samples with satisfactory results. The ratiometric strategy proposed in our study offers a sensitive and efficient approach for early diagnosis of AD, and this work will promote the further applications of engineered COFs in electrochemical sensors.

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.

Clinically oriented Alzheimer's biosensors: expanding the horizons towards point-of-care diagnostics and beyond

The development of minimally invasive and easy-to-use sensor devices is of current interest for ultrasensitive detection and signal recognition of Alzheimer's disease (AD) biomarkers. Over the years, tremendous effort has been made on diagnostic platforms specifically targeting neurological markers for AD in order to replace the conventional, laborious, and invasive sampling-based approaches. However, the sophistication of analytical outcomes, marker inaccessibility, and material validity strongly limit the current strategies towards effectively predicting AD. Recently, with the promising progress in biosensor technology, the realization of a clinically applicable sensing platform has become a potential option to enable early diagnosis of AD and other neurodegenerative diseases. In this review, various types of biosensors, which include electrochemical, fluorescent, plasmonic, photoelectrochemical, and field-effect transistor (FET)-based sensor configurations, with better clinical applicability and analytical performance towards AD are highlighted. Moreover, the feasibility of these sensors to achieve point-of-care (POC) diagnosis is also discussed. Furthermore, by grafting nanoscale materials into biosensor architecture, the remarkable enhancement in durability, functionality, and analytical outcome of sensor devices is presented. Finally, future perspectives on further translational and commercialization pathways of clinically driven biosensor devices for AD are discussed and summarized.

An excellent electrochemical aptasensor for amyloid-β oligomers based on a triple-helix aptamer switch via target-triggered signal transduction DNA displacement events

An excellent aptasensor for electrochemical detection of amyloid-β oligomers (AβOs) at trace levels was fabricated based on a triple-helix aptamer switch (THAS) via target-triggered signal transduction DNA displacement events. Specifically, a single-stranded anti-AβO aptamer (Apt) carrying two symmetrical arm segments was first attached via Au-S binding to an Au electrode. Gold nanoparticle (GNP)-tagged signal transduction probes (GNP-STPs) were simultaneously hybridized with the two arm segments of the Apt, and a rigid THAS was formed on the Au electrode. Compared to the conventional hybrid, the number of GNPs on the Au electrode increased significantly with the THAS, effectively improving the stability of the Apt to avoid lodging. Trithiocyanuric acid (TA) was utilized to further gather the GNPs and form network-like TA/GNPs. As a result, the differential pulse voltammetry (DPV) response of GNPs was clearly enhanced. When AβOs were present, target-triggered signal transduction DNA displacement events were carried out from THAS via the reaction of the Apt with the AβOs, which caused the GNP-STP to dissociate from the Au electrode, and thus a significant reduction in the DPV response was observed. The assay was able to sensitively detect trace AβOs by monitoring the AβO-controlled DPV response change. It exhibited a wide linear range from 1 fM to 10 pM with a low detection limit of 0.5 fM, and was successfully employed for the determination of AβOs in 20 serum samples, with good recovery. Moreover, the developed assay can provide a sensitive and selective platform for many studies or investigations related to Alzheimer's disease (AD) monitoring and treatment.

Recent Advances in the Detection of Antibiotic and Multi-Drug Resistant Salmonella: An Update

Antibiotic and multi-drug resistant (MDR) Salmonella poses a significant threat to public health due to its ability to colonize animals (cold and warm-blooded) and contaminate freshwater supplies. Monitoring antibiotic resistant Salmonella is traditionally costly, involving the application of phenotypic and genotypic tests over several days. However, with the introduction of cheaper semi-automated devices in the last decade, strain detection and identification times have significantly fallen. This, in turn, has led to efficiently regulated food production systems and further reductions in food safety hazards. This review highlights current and emerging technologies used in the detection of antibiotic resistant and MDR Salmonella.

Switchable electrochemical aptasensor for amyloid-β oligomers detection based on triple helix switch coupling with AuNPs@CuMOF labeled signaling displaced-probe

The aggregation of amyloid-β oligomers (AβOs) with extremely strong neurotoxicity has been proved to be the main pathogenesis of Alzheimer's disease (AD). For sensitive quantification of AβOs, a switchable electrochemical aptasensor is proposed. Metal organic framework carrying Au nanoparticles (AuNPs@CuMOF) has been used to label signaling displaced-probe (SD), which formed triple helix switch (THS) by hybridizing with label-free anti-AβOs aptamer (Apt) on the electrodeposited palladium electrode (EPd). Thus, a relatively strong response of differential pulse voltammetry (DPV) was produced (switch on). With the specific binding between AβOs and Apt, the DPV response obviously decreased, owing to destroyed structure of THS and the separation of AuNPs@CuMOF/SD from the EPd (switch off). The mode of "switch on-off" can dramatically enhance the AβOs-dependent DPV intensity change. As a result, the switchable EA exhibited excellent selectivity and sensitivity with the linear range from 0.5 fM to 500 fM and the detection limit of 0.25 fM. When evaluating the AβOs of artificial cerebrospinal fluid (aCSF) samples, the switchable EA exhibited desirable feasibility, and the results are basically consistent with the enzyme linked immunosorbent assay (ELISA). The work could provide a potential tool of the AD diagnosis and a bright future in clinical applications.

Post-Translational Modifications of BACE1 in Alzheimer's Disease

Beta-Amyloid Cleaving Enzyme1 (BACE1) is a monospecific enzyme for the key rate-limiting step in the synthesis of beta-amyloid(Aβ) from cleavage of amyloid precursor protein (APP), to form senile plaques and causes cognitive dysfunction in Alzheimer's disease (AD). Post-translation modifications of BACE1, such as acetylation, glycosylation, palmitoylation, phosphorylation, play a crucial role in the trafficking and maturation process of BACE1. The study of BACE1 is of great importance not only for understanding the formation of toxic Aβ but also for the development of an effective therapeutic target for the treatment of AD. This paper review recent advances in the studies about BACE1, with focuses being paid to the relationship of Aβ, BACE1 with post- translational regulation of BACE1. In addition, we specially reviewed studies about the compounds that can be used to affect post-translational regulation of BACE1 or regulate BACE1 in the literature, which can be used for subsequent research on whether BACE1 is a post-translationally modified drug.