Combining the Benefits of Biotin-Streptavidin Aptamer Immobilization with the Versatility of Ni-NTA Regeneration Strategies for SPR.

The high affinity of the biotin-streptavidin interaction has made this non-covalent coupling an indispensable strategy for the immobilization and enrichment of biomolecular affinity reagents. However, the irreversible nature of the biotin-streptavidin bond renders surfaces functionalized using this strategy permanently modified and not amenable to regeneration strategies that could increase assay reusability and throughput. To increase the utility of biotinylated targets, we here introduce a method for reversibly immobilizing biotinylated thrombin-binding aptamers onto a Ni-nitrilotriacetic acid (Ni-NTA) sensor chip using 6xHis-tagged streptavidin as a regenerable capture ligand. This approach enabled the reproducible immobilization of aptamers and measurements of aptamer-protein interaction in a surface plasmon resonance assay. The immobilized aptamer surface was stable during five experiments over two days, despite the reversible attachment of 6xHis-streptavidin to the Ni-NTA surface. In addition, we demonstrate the reproducibility of this immobilization method and the affinity assays performed using it. Finally, we verify the specificity of the biotin tag-streptavidin interaction and assess the efficiency of a straightforward method to regenerate and reuse the surface. The method described here will allow researchers to leverage the versatility and stability of the biotin-streptavidin interaction while increasing throughput and improving assay efficiency.

Pueraria montana (Kudzu vine) Ameliorate the Inflammation and Oxidative Stress against Fe-NTA Induced Renal Cancer.

Renal tissue plays a crucial function in maintaining homeostasis, making it vulnerable to xenobiotic toxicity. Pueraria montana has more beneficial potential against the various diseases and has long history used as a traditional Chinese medicine. But its effect against the renal cancer not scrutinize. The goal of this study is to see if Pueraria montana can protect rats from developing kidney tumors caused by diethylnitrosamine (DEN) and ferric nitrite (Fe-NTA). Wistar rats was selected for the current study and DEN (use as an inducer) and Fe-NTA (promoter) for induction the renal cancer. For 22 weeks, the rats were given orally Pueraria montana (12.5, 25, and 50 mg/kg) treatment. At regular intervals, the body weight and food intake were calculated. The rats were macroscopically evaluated for identification of cancer in the renal tissue. The renal tumor makers, renal parameters, antioxidant enzymes, phase I and II enzymes, inflammatory cytokines and mediators were estimated at end of the experimental study. Pueraria montana treated rats displayed the suppression of renal tumors, incidence of the tumors along with suppression of tumor percentage. Pueraria montana treated rats significantly (p < 0.001) increased body weight and suppressed the renal weight and food intake. It also reduced the level of renal tumor marker ornithine decarboxylase (ODC) and [3H] thymidine incorporation along with suppression of renal parameter such as uric acid, blood urea nitrogen (BUN), urea and creatinine. Pueraria montana treatment significantly (p < 0.001) altered the level of phase enzymes and antioxidant. Pueraria montana treatment significantly (p < 0.001) repressed the level of tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), interleukin-6 (IL-6) and improved the level of interleukin-10 (IL-10). Pueraria montana treatment suppressed the level of prostaglandin (PGE2), cyclooxygenase-2 (COX-2), nuclear kappa B factor (NF-κB) and transforming growth factor beta 1 (TGF-ß1). Pueraria montana suppressed the inflammatory necrosis, size the bowman capsules in the renal histopathology. Pueraria montana exhibited the chemoprotective effect via dual mechanism such as suppression of inflammatory reaction and oxidative stress.

Ferroptosis resistance determines high susceptibility of murine A/J strain to iron-induced renal carcinogenesis.

Cancer susceptibility is a critical factor in the understanding of carcinogenesis. Intraperitoneal (i.p.) injection of an iron chelate, ferric nitrilotriacetate (Fe-NTA), produces hydroxyl radicals via Fenton reaction to induce ferroptosis in renal proximal tubules. Rats or mice subjected to repeated i.p. injections of Fe-NTA develop renal cell carcinoma (RCC). To elucidate the molecular mechanisms that cause susceptibility to renal carcinogenesis, we first established an inter-strain difference in the susceptibility to Fe-NTA-induced renal carcinogenesis in mice. Based on a previous observation of a low incidence of RCC with this model in C57BL/6J strain mice, we investigated A/J strain mice here, which demonstrated significantly higher susceptibility to Fe-NTA-induced renal carcinogenesis. Homozygous deletion of the Cdkn2a/2b tumor suppressor locus was detected for the first time in A/J strain mice. Focusing on ferroptosis and iron metabolism, we explored the mechanisms involved that lead to the difference in RCC development. We compared the protective responses in the kidney of A/J and C57BL/6J strains after Fe-NTA treatment. After 3-week Fe-NTA treatment, A/J mice maintained higher levels of expression of glutathione peroxidase 4 and xCT (SLC7A11), leading to a lower level of lipid peroxidation. Simultaneously, A/J mice had decreased expression of transferrin receptor and increased expression of ferritin to greater degrees than C57BL/6 mice. After a single Fe-NTA injection, higher levels of oxidative cell damage and cytosolic catalytic Fe(II) were observed in C57BL/6J mice, accompanied by a greater increase in lipocalin-2. Lipocalin-2 deficiency significantly decreased oxidative renal damage. Our results suggest that a genetic trait favoring ferroptosis resistance contributes to high susceptibility to Fe-NTA-induced RCC in A/J strain.

The therapeutic potential of curcumin in alleviating N-diethylnitrosamine and iron nitrilotriacetate induced renal cell tumours in mice via inhibition of oxidative stress: Implications for cancer chemoprevention.

This study was designed to reveal the protective effects of dietary supplementation of curcumin against renal cell tumours and oxidative stress induced by renal carcinogen iron nitrilotriacetate (Fe-NTA) in ddY male mice. The results showed that mice treated with a renal carcinogen, Fe-NTA, a 35% renal cell tumour incidence was noticed, whereas renal cell tumour occurrence was elevated to 80% in Fe-NTA promoted and N-diethylnitrosamine (DEN)-initiated mice as compared with saline- treated mice. No incidence of tumours has been observed in DEN-initiated non-promoted mice. Diet complemented with 0.5% and 1.0% curcumin fed prior to, during and after treatment with Fe-NTA in DEN-initiated animals, tumour incidence was reduced dose-dependently to about 45% and 30% respectively. Immunohistochemical studies also revealed the increased formation of 4-hydroxy-2-nonenal (HNE)-modified protein adducts and 8-hydroxy-2'-deoxyguanosine (8-OHdG) in kidney tissue of mice treated with an intraperitoneal injection of Fe-NTA (6.0 mg Fe/kg body weight.). Furthermore, Fe-NTA treatment of mice also resulted in significant elevation of malondialdehyde (MDA), serum urea, and creatinine and decreases renal glutathione. However, the changes in most of these parameters were attenuated dose-dependently by prophylactic treatment of animals with 0.5% and 1% curcumin diet, this may be due to its antioxidative impact of curcumin. These results suggest that intake of curcumin is beneficial for the prevention of renal cell tumours and oxidative stress damage mediated by renal carcinogen, Fe-NTA.

Ni-Nitrilotriacetic Acid Affinity SELEX Method for Selection of DNA Aptamers Specific to the N-Cadherin Protein.

Nucleic acid aptamers are single-stranded oligonucleotides that may be evolved for affinity and specificity for their targets and can be easily produced, regenerated, and stabilized. In this study, we adapted Ni-NTA (nickle-charged nitrilotriacetic acid) affinity-chromatography in the development of single-stranded DNA aptamers against N-cadherin protein by systematic evolution of ligands by exponential enrichment (SELEX). After ten rounds of selection, two aptamers, designated NS13 and NC23, were selected, which showed low dissociation constants of 93 and 174 nM, respectively. The 5'-carboxyfluorescein-labeled NS13 was used for the sensitive detection of N-cadherin protein by the enzyme-linked oligonucleotide assay (ELONA) method.

Ultrafast in-gel detection by fluorescent super-chelator probes with HisQuick-PAGE.

Polyacrylamide gel electrophoresis (PAGE) and immunoblotting (Western blotting) are the most common methods in life science. In conjunction with these methods, the polyhistidine-tag has proven to be a superb fusion tag for protein purification as well as specific protein detection by immunoblotting, which led to a vast amount of commercially available antibodies. Nevertheless, antibody batch-to-batch variations and nonspecific binding complicate the laborious procedure. The interaction principle applied for His-tagged protein purification by metal-affinity chromatography using N-nitrilotriacetic acid (NTA) was employed to develop small high-affinity lock-and-key molecules coupled to a fluorophore. These multivalent NTA probes allow specific detection of His-tagged proteins by fluorescence. Here, we report on HisQuick-PAGE as a fast and versatile immunoblot alternative, using such high-affinity fluorescent super-chelator probes. The procedure allows direct, fast, and ultra-sensitive in-gel detection and analysis of soluble proteins as well as intact membrane protein complexes and macromolecular ribonucleoprotein particles.

High-efficiency Ni2+-NTA/PAA magnetic beads with specific separation on His-tagged protein.

To effective capture and universal enrichment of His-tagged protein, polyacrylic acid (PAA) brushes were used to encapsulate Fe3O4 nanoparticles, connect NTA, and Ni2+ to prepare magnetic beads. These materials provide many advantages, such as excellent stability, tuneable particle size, and a surface for further functionalisation with biomolecules. His-tagged green fluorescence protein (GFP) was separated efficiently, and the binding capacity of Fe3O4/MPS@PAA/NTA-Ni2+ was 93.4 mg/g. Compared with High-Affinity Ni-NTA Resin and Ni-NTA Magnetic Agarose Beads, Fe3O4/MPS@PAA/NTA-Ni2+ nanocomposites exhibited higher separation efficiency and binding capacity towards His-tagged GFP. Moreover, the selectivity and recyclability of them for the target proteins were maintained well after six cycles. This study would widen the application of PAA in constructing multifunctional nanocomposites for biomedical fields.

Cathepsin B pH-Dependent Activity Is Involved in Lysosomal Dysregulation in Atrophic Age-Related Macular Degeneration.

Age-related macular degeneration (AMD) is characterized by retinal pigment epithelial (RPE) cell dysfunction beginning at early stages of the disease. The lack of an appropriate in vitro model is a major limitation in understanding the mechanisms leading to the occurrence of AMD. This study compared human-induced pluripotent stem cell- (hiPSC-) RPE cells derived from atrophic AMD patients (77 y/o ± 7) to hiPSC-RPE cells derived from healthy elderly individuals with no drusen or pigmentary alteration (62.5 y/o ± 17.5). Control and AMD hiPSC-RPE cell lines were characterized by immunofluorescence, flow cytometry, and electronic microscopy. The toxicity level of iron after Fe-NTA treatment was evaluated by an MTT test and by the detection of dichloro-dihydro-fluorescein diacetate. Twelve hiPSC-RPE cell lines (6 AMD and 6 controls) were used for the experiment. Under basal conditions, all hiPSC-RPE cells expressed a phenotypic profile of senescent cells with rounded mitochondria at passage 2. However, the treatment with Fe-NTA induced higher reactive oxygen species production and cell death in hiPSC-RPE AMD cells than in hiPSC-RPE Control cells. Interestingly, functional analysis showed differences in lysosomal activity between the two populations. Indeed, Cathepsin B activity was higher in hiPSC-RPE AMD cells compared to hiPSC-RPE Control cells in basal condition and link to a pH more acidic in this cell population. Moreover, oxidative stress exposure leads to an increase of Cathepsin D immature form levels in both populations, but in a higher proportion in hiPSC-RPE AMD cells. These findings could demonstrate that hiPSC-RPE AMD cells have a typical disease phenotype compared to hiPSC-RPE Control cells.

Space-confined pyrolysis for fabrication of peacods-like Fe3O4@C-Ni nanostructures for catalysis and protein adsorption.

A unique nanostructure of Fe3O4 nanoparticles (NPs)-in/carbon layer/out-Ni NPs was developed and proved to be an efficient catalyst and protein adsorbent. This kind of nanostructure was formed through a space-confined pyrolysis procedure using polydopamine-Ni2+ coated Fe-NTA nanowires as the precursor. A N-doped carbon interlayer derived from polydopamine (PDA) supported a large amount of Ni NPs and entrapped well-defined Fe3O4 NPs, which were obtained through reduction of Ni2+, Fe3+ by carbonized NTA groups and a PDA layer. The contributions of the unique configuration along with the high density of Ni NPs in Fe3O4@C-Ni are significant for improving catalysis and protein adsorption performance, which is expected to be a promising alternative to other conventional catalysts and protein adsorbents. Due to the unique novel nanostructure, this nanocomposite possesses a wide range of applications, not only for catalytic reactions but also for other inhomogeneous reactions.

Detection and quantification of transition metal leaching in metal affinity chromatography with hydroxynaphthol blue.

The widespread use of immobilized metal-affinity chromatography (IMAC) for fast and efficient purification of recombinant proteins has brought potentially toxic transition elements into common laboratory usage. However, there are few studies on the leaching of metal from the affinity resin, such as nickel-nitrilotriacetic acid (Ni-NTA), with possible deleterious impact on the biological activity. This is of particular importance when reducing or chelating eluants stronger than imidazole are used. We present a detailed study of hydroxynaphthol blue (HNB) as an indicator of several divalent metal cations, but with emphasis on Ni2+, clarifying and correcting many errors and ambiguities in the older literature on this dye compound. The assay is simple and sensitive and many metals, notably Ni2+, Zn2+, Cu2+, Pb2+, Fe2+, Co2+, and Al3+, can be readily detected and quantified at concentrations down to 15-50 nM (1-5 ppb) at neutral pH and in most commonly used buffers using spectroscopic equipment available in typical biochemistry research labs. Using this method, we show that significant amounts of Ni2+ (up to 20 mM) are co-purified with a target protein (cytochrome bc1 complex) when histidine is used to elute from Ni-NTA resin.

Protein Microarray Copying: Easy on-Demand Protein Microarray Generation Compatible with Fluorescence and Label-Free Real-Time Analysis.

Protein microarrays are essential to understand complex protein interaction networks. Their production, however, is a challenge and renders this technology unattractive for many laboratories. Recent developments in cell-free protein microarray generation offer new opportunities, but are still expensive and cumbersome in practice. Herein, we describe a cost-effective and user-friendly method for the cell-free production of protein microarrays. From a polydimethylsiloxane (PDMS) flow cell containing an expressible DNA microarray, proteins of interest are synthesised by cell-free expression and then immobilised on a capture surface. The resulting protein microarray can be regarded as a "copy" of the DNA microarray. 2 His6 - and Halo-tagged fluorescent reference proteins were used to demonstrate the functionality of nickel nitrilotriacetic acid (Ni-NTA) and Halo-bind surfaces in this copy system. The described process can be repeated several times on the same DNA microarray. The identity and functionality of the proteins were proven during the copy process by their fluorescence and on the surface through a fluorescent immune assay. Also, single-colour reflectometry (SCORE) was applied to show that, on such copied arrays, real-time binding kinetic measurements were possible.

Folding and Assembly of Vanilloid Receptor Secondary-Structure Peptide with Hexahistidine Linker at Nickel-Nitrilotriacetic Acid Monolayer for Capsaicin Recognition.

Herein, we report the self-assembly of a synthetic vanilloid receptor (VR) peptide that selectively binds capsaicin. We synthesized a 26-mer peptide-YSEILFFVQS-HHHHHH-LAMGWTNMLY (S3HS4)-comprising two chemoreceptor domains of transient receptor potential channel (TRPV1) linked by a hexahistidine sequence. High-speed atomic force microscopy (AFM) imaging in water revealed that the peptide structures alternated rapidly between wedge shape and linear forms. Circular dichroism spectroscopy showed that 65% of the amide units in the peptide chain adopted an α-helix structure, which was ascribed to the chemoreceptor domains. S3HS4 developed well-packed monolayers at the Ni-treated thiolated nitrilotriacetic acid self-assembled monolayers by chelation of the hexahistidine segment, as characterized by infrared spectroscopy and AFM, which exhibited statistically constant specific height. Therefore, S3HS4 was expected to fold spontaneously upon chelation, and the resulting helix-turn-helix conformers developed films while uniformly oriented: the tilt angle was 69° from the surface normal to the substrate. According to microgravimetric analysis using a quartz crystal microbalance (QCM), the adsorption was 84 ± 47 pmol cm-2 ( n = 3), which was almost consistent with the saturation adsorption of an α-helix unit. We also used a QCM to investigate the host-guest reactions of S3HS4 and found that the S3HS4-attached QCM-chip-bound capsaicin with an apparent binding constant of (4.2 ± 3.6) × 104 M-1 ( n = 4), whereas there was no evidence of binding to vanillin or acetophenone. Two controls-a blank chip without S3HS4 and a chip modified with a single helical peptide (LAMGWTNMLY-HHHHHH)-produced no capsaicin response. To the best of our knowledge, S3HS4 is the first example of a synthetic VR mimic peptide. We believe that the present surface-directed structure-based design can be used to exploit the α-helix bundle in hexahistidine-linked bishelical peptides.

Modification of phage display technique for improved screening of high-affinity binding peptides.

The phage display technique is a combinatorial technology in which random peptides are displayed on the surface of the phage; it is widely used to identify high-affinity peptides that bind to a target protein. However, this technique presents several problems due to non-specific binding of the phages and steric hindrance caused by blocking agents. To overcome these problems, we tested two modified methods and compared their screening performance with that of the conventional method. We used poly-His-tagged human epidermal growth factor receptor 2 (HER2) as a target protein and silica-coated magnetic particles (MPs) with an immobilized nickel-nitrilotriacetic acid ligand as a solid matrix. Modified method #1 (#M1) included two negative selection steps against a blocking agent (bovine serum albumin) and nude Ni-NTA MPs, after the positive selection step using immobilized HER2 on MPs in the absence of BSA. Modified method #2 (#M2) allowed the binding of phages and HER2 in solution prior to immobilizing HER2 on the MP surface. The negative selection procedure was the same between them. The binding affinity of the phages screened by #M1 and #M2 was evaluated by phage ELISA. Two phages from #M2 (#M2-4 and 5) showed the highest binding, and between them #M2-5 was selected for affinity maturation by inserting a hairpin-structured peptide between the two #M2-5 peptides. SPR study showed the HER2-binding affinity was indeed improved by ca. 2000-fold to become comparable with that of the intact antibody (trastuzumab). The modified biopanning methods combined with the dimerization maturation can be an effective way to develop antibody-mimicking peptides for affinity binding.

Affinity Purification of Methyllysine Proteome by Site-Specific Covalent Conjugation.

A basic but critical step in targeted proteomics by mass spectrometry is the separation of the targeted proteins from the complex mixture of the whole proteome by affinity purification. The bait protein is usually immobilized on the surface of a solid support to enable affinity-based purification of the targeted proteome. Here, we developed a site-specific covalent immobilization of the bait protein through affinity-guided covalent coupling (AGCC) of a single cysteine residue of an SH2 domain (utilized as an affinity tag for the protein target) with an engineered ligand peptide. Site-specific covalent immobilization of a methyllysine-binding protein HP1ß chromodomain on the agarose resin was used to purify the methyllysine proteome from the whole-protein mixture. This new bait immobilization led to a notably low background in the affinity purification step, markedly outperforming the conventional (His)6 tag-nickel nitrilotriacetic acid (Ni-NTA) immobilization method. Subsequent analysis of the purified proteome identified 275 lysine methylated sites and 184 methylated proteins from 332 HP1ß CD-binding proteins, including 30 novel methylated proteins. This work demonstrates that a robust site-specific covalent protein immobilization method is well-suited for proteomic analysis of low-abundance proteins. This method also enables the identification of new methylated proteins and methylation sites in the methyllysine proteome.

Design and synthesis of cell-permeable fluorescent nitrilotriacetic acid derivatives.

Fluorescence labeling of the target molecules using a small molecule-based probe is superior than a method using genetically expressed green fluorescence protein (GFP) in terms of convenience in its preparation and functionalization. Fluorophore-nitrilotriacetic acid (NTA) conjugates with several ester protecting groups were synthesized and evaluated for their cell membrane permeability by fluorescence microscopy analysis. One of the derivatives, acetoxymethyl (AM)-protected NTA conjugate is hydrolyzed, resulting in intracellular accumulation, thus providing localized fluorescence intensity in cells. This modification is expected as an effective method for converting a non-cell membrane permeable NTA-BODIPY conjugates to a cell membrane permeable derivatives.

Anti-carcinogenic effect of hesperidin against renal cell carcinoma by targeting COX-2/PGE2 pathway in Wistar rats.

The present study was designed to evaluate the protective effects of hesperidin, a flavonoid on DEN initiated and Fe-NTA promoted renal carcinogenesis in Wistar rats. Renal cancer was initiated by a single i.p. injection of DEN (200 mg/kg b.wt.) and promoted with Fe-NTA (9 mg Fe/kg b.wt. i.p.) twice a week for 16 weeks. Rats were simultaneously administered with hesperidin (100 and 200 mg/kg b.wt.) for 16 consecutive weeks. The chemopreventive effect of hesperidin was assessed in terms of antioxidant activities, renal function, PGE2 level, and the expressions of COX-2 and VEGF. Hesperidin decreased the DEN and Fe-NTA induced lipid peroxidation, improved the renal function (by decreasing the levels of BUN, creatinine, and KIM-1) and restored the renal antioxidant armory (GSH, GPx, GR, SOD, and catalase). Hesperidin was also found to decrease the level of PGE2 and downregulate the expressions of COX-2 and VEGF. Histological findings further revealed the protective effects of hesperidin against DEN and Fe-NTA induced kidney damage. The result of our present findings suggest that hesperidin may be a promising modulator in preventing renal cancer possibly by virtue of its ability to alleviate oxidative stress and inhibit COX-2/PGE2 pathway.

Orthogonal supramolecular protein assembly on patterned bifunctional surfaces.

We report successful and selective dual protein assembly on patterned bifunctional ßCD-Ni(ii)NTA surfaces, using red fluorescent protein variants with hexahistidine-tags and teal fluorescent protein variants conjugated with a peptide containing three adamantyl groups. We show that dual protein patterns can only be assembled, when opposing supramolecular interactions have been optimized and nonspecific interactions have been sufficiently suppressed.

Development of a Small Hybrid Molecule That Mediates Degradation of His-Tag Fused Proteins.

In recent years, the induction of target-protein degradation via the ubiquitin-proteasome system (UPS) mediated by small molecules has attracted attention, and this approach has applications in pharmaceutical development. However, this technique requires a ligand for the target protein that can be incorporated into tailor-made molecules, and there are many proteins for which such ligands have not been found. In this study, we developed a protein-knockdown method that recognizes a His-tag fused to a protein of interest. This strategy theoretically allows comprehensive targeting of proteins of interest by a particular molecule recognizing the tag. As expected, our hybrid molecule 10 [SNIPER(CH6)] efficiently degraded His-tagged CRABP-II and Smad2 in cells. This system provides an easy method to determine the susceptibility of proteins of interest to UPS-mediated degradation. Furthermore, we hope that this method will become an efficient tool to analyze the function of the UPS.

Fenton reaction-induced renal carcinogenesis in Mutyh-deficient mice exhibits less chromosomal aberrations than the rat model.

Oxidative stress including iron excess has been associated with carcinogenesis. The level of 8-oxoguanine, a major oxidatively modified base in DNA, is maintained very low by three distinct enzymes, encoded by OGG1, MUTYH and MTH1. Germline biallelic inactivation of MUTYH represents a familial cancer syndrome called MUTYH-associated polyposis. Here, we used Mutyh-deficient mice to evaluate renal carcinogenesis induced by ferric nitrilotriacetate (Fe-NTA). Although the C57BL/6 background is cancer-resistant, a repeated intraperitoneal administration of Fe-NTA induced a high incidence of renal cell carcinoma (RCC; 26.7%) in Mutyh-deficient mice in comparison to wild-type mice (7.1%). Fe-NTA treatment also induced renal malignant lymphoma, which did not occur without the Fe-NTA treatment in both the genotypes. Renal tumor-free survival after Fe-NTA treatment was marginally different (P = 0.157) between the two genotypes. Array-based comparative genome hybridization analyses revealed, in RCC, the loss of heterozygosity in chromosomes 4 and 12 without p16INKA inactivation; these results were confirmed by a methylation analysis and showed no significant difference between the genotypes. Lymphomas showed a preference for genomic amplifications. Dlk1 inactivation by promoter methylation may be involved in carcinogenesis in both tumors. Fe-NTA-induced murine RCCs revealed significantly less genomic aberrations than those in rats, demonstrating a marked species difference.

The Natural Product Curcumin as a Potential Coadjuvant in Alzheimer's Treatment.

Alzheimer's disease (AD) is a neurodegenerative disease characterized by a progressive cognitive impairment of patients, affecting around 12% of people older than 65 years old. WHO estimated that over 48.6 million all over the world suffer this disease. On the basis of cumulative results on our research, we have postulated the neuroimmunomodulation hypothesis that appears to provide a reasonable explanation of both the preclinical and clinical observations. In this context, the long-term activation of the innate immune system triggers an anomalous cascade of molecular signals, finally leading to tau oligomerization in the pathway to neuronal degeneration. In the present scenario of the failure of many anti-AD drugs, nutraceutical compounds provide an avenue for AD prevention and possibly as coadjuvants in the treatment of this disease. Recent discoveries point to the relevance of curcumin, a natural anti-inflammatory agent, in controlling oxidative stress and improving cholinergic function in the brain, even though the mechanisms underlying these actions are unknown. We investigated the effects of curcumin in cultures of neuronal cells. For this study, we exposed cells to prooxidant conditions, both in the presence and absence of curcumin. Our data reveal that curcumin exert a strong neuroprotective effect in N2a cells, thus preventing toxicity by oxidative agents H2O2 and Fe+3. This is supported by results that indicate that curcumin control the neurodegenerative effects of both oxidative agents, relieving cells from the loss of neuritogenic processes induced by prooxidants. In addition, curcumin was able to slow down the tau aggregation curve and disassemble tau pathological oligomeric structures. Data suggest that curcumin could be a potential compound for prevention of cognitive disorders associated with AD.