Cellular Fluorescence Research Articles

Preparation of AS1411 Aptamer Modified Mn-MoS2 QDs for Targeted MR Imaging and Fluorescence Labelling of Renal Cell Carcinoma.

BackgroundEarly diagnosis of renal cell carcinoma is extremely significant for the effective treatment of kidney cancer. The development of AS1411 aptamer modified Mn-MoS2 QDs provides a promising fluorescence/magnetic resonance (MR) dual-modal imaging probe for the precise diagnosis of renal clear cell carcinoma.MethodsIn this work, Mn-MoS2 QDs were synthesized through a simple “bottom-up” one-step hydrothermal method. AS1411 aptamer was modified on the Mn-MoS2 QDs to improve the specificity to renal cell carcinoma. The characteristics of Mn-MoS2 QDs were confirmed by transmission electronic microscopy (TEM), atomic force microscope (AFM), X-ray photoelectron spectrometer (XPS), photoluminescence (PL) emission spectra, etc. Cellular fluorescence labelling was investigated using the Mn-MoS2 QDs and AS1411-Mn-MoS2 QDs. The T1-weighted MR imaging was assessed by the in vitro MR cell imaging and in vivo MR imaging. Finally, the long-term toxicity of Mn-MoS2 QDs was investigated by the hematology and histological analysis.ResultsThe prepared Mn-MoS2 QDs exhibited excellent aqueous property, intense fluorescence, low toxicity, high quantum yield of 41.45% and high T1 relaxivity of 16.95 mM−1s−1. After conjugated with AS1411 aptamer, the AS1411-Mn-MoS2 QDs could specifically fluorescently label the renal carcinoma cells and present a specific MRI signal enhancement in the tumor region of mice bearing renal carcinoma tumors. Furthermore, Mn-MoS2 QDs revealed low toxicity to the mice via hematology and histological analysis.ConclusionThese results demonstrated the potential of AS1411-Mn-MoS2 QD as a novel nanoprobe for targeted MR imaging and fluorescence labelling of renal cell carcinoma.

New carbazole fluorescent sensor for ultrasensitive and ratiometric sensing of SO2 derivatives and hydrazine

The probe CBTA is a novel bifunctional fluorescent probe that can detect bisulfite and hydrazine hydrate in a rational manner. And probe CBTA could specifically detect bisulfite and hydrazine hydrate among different analytes. Moreover, the response time of probe CBTA to SO2 derivatives and hydrazine is extremely short, and the detection limits for bisulfite and hydrazine are as low as 5.6 nmol and 39 nmol. Cellular experiments also indicated that the probe CBTA was low in cytotoxicity and could be applied to cellular fluorescence imaging. Therefore, the probe CBTA could provide an efficient means for detecting SO2 derivatives and hydrazine in vitro.

Radioiodinated tyrosine based carbon dots with efficient renal clearance for single photon emission computed tomography of tumor

Nanoparticles with effective tumor accumulation and efficient renal clearance have attracted significant interests for clinical applications. We prepared 2.5 nm tyrosine based carbon dots (TCDs) with phenolic hydroxyl groups on the surface for directly 125I labeling. The 125I labeled polyethylene glycol (PEG) functionalized TCDs (125I-TCDPEGs) showed excellent radiochemical stability both in vitro and in vivo. Due to the enhanced permeability and retention effect, these 125I-TCDPEGs demonstrated a tumor accumulation around 4%–5% of the injected dose per gram (ID/g) for U87MG, 4T1, HepG2 and MCF7 tumor-bearing mice at 1 h post-injection. Meanwhile, the 125I-TCDPEGs also could be fast renally excreted, with less than 0.6% ID/g left in the liver and spleen within 24 h. These radioactive carbon dots not only can be used for cellular fluorescence imaging due to their intrinsic optical property, but are also effective single photon emission computed tomography (SPECT) imaging agents for tumor. Together with their excellent biocompatibility and stability, we anticipate these 125I-TCDPEGs of great potential for early tumor diagnosis in clinic. What’s more, our TCDPEGs are also proved to be feasible carriers for other iodine isotopes such as 127I and 131I for different biomedical application.

One pot preparation of polyurethane‐based GSH‐responsive core‐shell nanogels for controlled drug delivery

ABSTRACTIn this work, we present a new type of glutathione (GSH)‐responsive polyurethane‐based core‑shell nanogels (RS‐CS‐PUNGs) with hydrophilic methoxypolyethylene glycols (mPEG) shell, which was prepared by a one‐pot synthetic method. The obtained RS‐CS‐PUNGs not only show a good size distribution with the hydrodynamic radii around of 20 nm, but also exhibit good stability in the organic solvent. The results demonstrate that GSH (10 mM) trigger the nanogel swelling and accelerate the loaded drug release in PBS (pH = 7.4). Although the RS‐CS‐PUNGs loaded with DOX show a slower cellular uptake behavior than the free doxorubicin (DOX), which is likely caused by the controlled drug release property of the nanocarrier, the enhanced cellular uptake fluorescence intensity of RS‐CS‐PUNGs loaded with DOX is still observed compared to the control group. Both MTT and CCK‐8 assay indicate that although an obvious lower initial cytotoxicity is observed compared to free DOX at 24 h postincubation, the cytotoxicity of the RS‐CS‐PUNGs loaded with DOX is obvious enhanced after treated 72 h, which stayed at the similar level with free DOX. Attributing to the easy preparation progress and GSH‐responsive property, RS‐CS‐PUNGs maybe hold the potential for further application in the field of drug delivery. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48473.

Two-photon excitation nanoprobe for DNases activity imaging assay in hepatic ischemia reperfusion injury

We report the use of a novel two-photon excitation (TPE) nanoprobe in a DNase activity assay in vitro and ex vivo. This nanoprobe was mainly composed of a gold nanoparticle (AuNP) core as the cellular transporter and fluorescence quencher, and two-photon absorption dyes (TP dyes) that were inserted into the double-stranded DNA (dsDNA) as the reporter element. In the presence of DNases, the dsDNA immobilized onto the AuNP surface can be hydrolyzed into DNA fragments, thus resulting in the release of large amounts of TP dyes, the fluorescence recovery of the TP dyes and the activity measurement of DNases. This TPE nanoprobe has been successfully used to monitor the DNase activity in living cells and a hepatic ischemia reperfusion injury rat model.

2-Vinylfuran substituted BODIPY H2S fluorescent turn on probe based on hydrolysis of furfural and nucleophilic addition of double bond

In this work, a fluorescent H2S turn on probe BODIPY-vinylfuran has been synthesized by reaction of 8-methyl-BODIPY with functional group 5-methylfuranal. When H2S is present, the furan ring is hydrolyzed and ring-opened, and H2S further undergoes a nucleophilic addition reaction with carbon-carbon double bond (CC) of vinylfuran, resulting in enhanced fluorescence. Due to the addition reaction of carbon-carbon double bond with H2S, the π-π conjugated structure of furan and BODIPY is destroyed, resulting in the shifting of maximum emission peak from 535 nm to 496 nm. Sensor BODIPY-vinylfuran demonstrates remarkable performance with more than 150-folds increase in fluorescence intensity, low detection limit (99.4 nM) and selectivity to H2S specificity. Furthermore, BODIPY-vinylfuran possesses low cytotoxicity and good biocompatibility. Cellular fluorescence imaging further demonstrates that BODIPY-vinylfuran is highly responsive to both endogenous and exogenous H2S.

BHLH-PAS protein RITMO1 regulates diel biological rhythms in the marine diatom Phaeodactylum tricornutum

Periodic light-dark cycles govern the timing of basic biological processes in organisms inhabiting land as well as the sea, where life evolved. Although prominent marine phytoplanktonic organisms such as diatoms show robust diel rhythms, the mechanisms regulating these processes are still obscure. By characterizing a Phaeodactylum tricornutum bHLH-PAS nuclear protein, hereby named RITMO1, we shed light on the regulation of the daily life of diatoms. Alteration of RITMO1 expression levels and timing by ectopic overexpression results in lines with deregulated diurnal gene expression profiles compared with the wild-type cells. Reduced gene expression oscillations are also observed in these lines in continuous darkness, showing that the regulation of rhythmicity by RITMO1 is not directly dependent on light inputs. We also describe strong diurnal rhythms of cellular fluorescence in wild-type cells, which persist in continuous light conditions, indicating the existence of an endogenous circadian clock in diatoms. The altered rhythmicity observed in RITMO1 overexpression lines in continuous light supports the involvement of this protein in circadian rhythm regulation. Phylogenetic analysis reveals a wide distribution of RITMO1-like proteins in the genomes of diatoms as well as in other marine algae, which may indicate a common function in these phototrophs. This study adds elements to our understanding of diatom biology and offers perspectives to elucidate timekeeping mechanisms in marine organisms belonging to a major, but under-investigated, branch of the tree of life.

Synthesis and characterization of cell-laden double-network hydrogels based on silk fibroin and methacrylated hyaluronic acid

Repair or regeneration of load-bearing soft tissue is one of the great challenges in tissue engineering and regenerative medicine. The main obstacle is mismatch between the properties of most synthetic biomaterials and the target tissue, such as the biomechanical performance. Currently, development of novel hydrogels with high mechanical strength and biocompatibility is the main goal of load-bearing soft tissue engineering. In the paper, a double-network hydrogel strategy involving silk fibroin and methacrylated hyaluronic acid was utilized to synthesize hydrogels through a combination of sonication and photopolymerization. Furthermore, due to the biocompatibility of the entire fabrication process, preosteoblast cells could be encapsulated within the hydrogel with high viability. The hydrogel characterization results demonstrated that the SF-HAMA hydrogels have many excellent properties, such as high mechanical strength, high water content, a slow degradation rate and biocompatibility. Two-dimensional cell experiments confirmed that the preosteoblasts could quickly attach and subsequently proliferate on the hydrogels, shown by cellular fluorescence staining. In addition, the studies of preosteoblast encapsulation and the following fluorescent staining demonstrated that the DN hydrogel could support proliferation and spreading of encapsulated cells, which suggests promising application of the hydrogel in the soft tissue engineering field.

In vitro model for assessing the effect of T helper cell cytokines on the barrier function of alveolar type II epithelial cells

Abstract There are still diseases of global burden for which satisfactory vaccines are unavailable, e.g. tuberculosis. Vaccines against intracellular microbes has relied on the activation of the adaptive T cell response. Our laboratory is interested in investigating whether the innate epithelial host defense could be integrated in a novel approach. In response to airborne pathogens, airway epithelia release antimicrobial peptides like human beta defensin-2 and -3 (HBD2/3), antimicrobial lipids, and chemokines, like IL-8, to attract other immune cells including T helper cells that are integral to the adaptive immune response. We hypothesize that T cell derived cytokines augment the antimicrobial function of airway epithelia and we have developed an in vitro model to generate pilot data. A549 cells, alveolar type II epithelial cells, were grown in air-liquid interface and stimulated with TNF-α & IFN-γ and IL-17 & IL-22, at 5 ng/mL each, for 24 h. IL-8 and HBD2/3 gene expression was quantified by RT-PCR and secretion of antimicrobial peptides was assessed by AU-PAGE and Western blot probing for HBD2/3. Lipid production was assessed with Bodipy and the physical barrier integrity with Phalloidin. IL-8 gene expression was 9-fold elevated when cells were stimulated with TNF-α & IFN-γ. Secretions from stimulated cells appeared to contain more cationic peptides that were not reactive with HBD2/3 polyclonal antibodies. Cellular Bodipy fluorescence was pronounced after IL-17 & IL22 stimulation. Phalloidin staining was consistent with tight junction formation in all samples. This data provides evidence that T helper cells may directly augment epithelial barrier function supporting a novel vaccine design that integrates the epithelial cell response.

Glutathione S‐transferase omega 1 inhibition activates JNK‐mediated apoptotic response in breast cancer stem cells

Glutathione S-transferase omega 1 (GSTO1) contributes to the inactivation of a wide range of drug compounds via conjugation to glutathione during phase reactions. Chemotherapy-induced GSTO1 expression in breast cancer cells leads to chemoresistance and promotes metastasis. In search of novel GSTO1 inhibitors, we identified S2E, a thia-Michael adduct of sulfonamide chalcone with low LC50 (3.75±0.73μm) that binds to the active site of GSTO1, as revealed by molecular docking (glide score: -8.1), cellular thermal shift assay and fluorescence quenching assay (Kb ≈10×105 mol·L-1 ). Docking studies confirmed molecular interactions between GSTO1 and S2E, and identified the hydrogen bond donor Val-72 (2.14Å) and hydrogen bond acceptor Ser-86 (2.77Å). Best pharmacophore hypotheses could effectively map S2E and identified the 4-methyl group of the benzene sulfonamide ring as crucial to its anti-cancer activity. Lack of a thiophenyl group in another analog, 2e, reduced its efficacy as observed by cytotoxicity and pharmacophore matching. Furthermore, GSTO1 inhibition by S2E, along with tamoxifen, led to a significant increase in apoptosis and decreased migration of aggressive MDA-MB-231 cells, as well as significantly decreased migration, invasion and mammosphere formation in sorted breast cancer stem cells (CSCs, CD24- /CD44+ ). GSTO1 silencing in breast CSCs also significantly increased apoptosis and decreased migration. Mechanistically, GSTO1 inhibition activated the c-Jun N-terminal kinase stress kinase, inducing a mitochondrial apoptosis signaling pathway in breast CSCs via the pro-apoptotic proteins BAX, cytochrome c and cleaved caspase 3. Our study elucidated the role of the GSTO1 inhibitor S2E as a potential therapeutic strategy for preventing chemotherapy-induced breast CSC-mediated cancer metastasis and recurrence.

Transfection of the TRAIL gene into human mesenchymal stem cells using biocompatible polyethyleneimine carbon dots for cancer gene therapy

For effective gene therapy using Tumor necrosis factor-Related Apoptosis-Inducing Ligand (TRAIL), which is a protein that selectively induces cancer cell apoptosis through human mesenchymal stem cells (hMSCs), low cytotoxicity branched polyethyleneimine (bPEI) 25k carbon dots (bPEI25k CDs) were investigated as a TRAIL–GFP gene (plasmid TRAIL–GFP, pTRAIL–GFP) carrier for delivery into hMSCs. bPEI25k CDs were prepared using one-step microwave-assisted pyrolysis, which has the advantage of low cytotoxicity and allows for bioimaging after gene delivery. The bPEI25k CDs had lower cytotoxicity levels at all tested concentrations, whereas the raw bPEI25k were cytotoxic in proportions up to a concentration by 25%. The complex containing bPEI25k CDs and pTRAIL–GFP was safely internalized and transfected into the hMSCs. It also revealed a cellular fluorescence imaging property induced by a unique characteristic of CDs. The amount of secreted TRAIL from bPEI25k CDs/pTRAIL–GFP@hMSCs was 25-fold higher than that from bPEI25k/pTRAIL–GFP@hMSCs, leading to a higher cytotoxic effect against the lung cancer cells. Therefore, bPEI25k CDs are recommended as an effective gene carrier for successful cancer gene therapy mediated through hMSCs.

Valve teratologies and Chl c in the freshwater diatom Tabellaria flocculosa as biomarkers for metal contamination

Freshwater benthic diatoms, routinely used for bioassessment, are potential metal indicators because of their known capacity to reflect changes in water chemistry. Nevertheless, the effect of metals on benthic freshwater diatoms is still poorly understood. Metals, such as Zn and Cu, are not only essential as micronutrients, but also one of the main anthropogenic pressures in aquatic ecosystems. However, metal stress cannot be detected with the current European standard methods using bioindicators for environmental assessment, so new tools need to be developed. We studied the effects of Zn and Cu on the freshwater diatom Tabellaria flocculosa. This diatom isolated from a Zn and Cu contaminated stream, was exposed to different concentrations of Zn and Cu, and the metal effects were assessed by measuring physiological ((growth, fluorescence, pigments’ content (Chl a, c, carotenoids)) and morphological parameters (teratological forms). We found that at environmental concentrations occurring in European streams, Zn and Cu showed toxic effects on T. flocculosa. Toxic effects induced by Zn were only observed at high concentrations (500 and 1000 µg/L), resulting in fluorescence changes, an increase of Chl c cellular content and an increase of teratological forms (with an increase of more heavily deformed valves with increasing metal concentrations). Increasing Cu exposure induced several changes, such as increasing the cellular content of Chl a and c, while carotenoids’ cellular content decreased. Cu also increased the number of T. flocculosa frustule deformations. Cu did not affect the cellular fluorescence. Our results thus show that the frequency of diatom teratologies could potentially be used to assess metal stress for the studied metals Zn and Cu. Additionally, the analysis of algal pigments could potentially separate the effects of different metals.

Tumor cell-on fluorescence imaging agent using hyaluronate dots

We report here the use of near-infrared fluorescent dye-labelled hyaluronate (HA) dot named HDFc for tumor imaging. We took advantage of the unique auto-quenching characteristic that occurs when the fluorescent dye molecules are in close proximity to one another under ordinary conditions. However, when the HDFc is located in tumor cells, the tumor cell-specific enzyme (e.g., hyaluronidase: HAase) affects the structure of the HDFc, followed by the transition from auto-quenched dye molecules to dequenched dye molecules, resulting in the identification of the tumor cells. For this purpose, HDFcs were synthesized, characterized, and exogenously treated with HAase to demonstrate the enzyme-dependent HDFc photoactivity. Specifically, confocal microscopy and flow cytometry confirmed the efficient cellular internalization and fluorescence production of HDFc in CD44+ and HAase-abundant tumor cells. Collectively, this study opens the door for utilizing polymeric dots to visualize tumor cells by introducing biocompatible HA and tumor cell-on photoluminescent dye.

Novel algorithm for analysis of cellular fluorescence spectrum based on optimization iteration

Novel algorithm for analysis of cellular fluorescence spectrum based on optimization iteration

Rapid detection and cellular fluorescence imaging of the TBI biomarker Let-7i using a DNA–AgNC nanoprobe

Rapid fluorescence detection of Let-7i for TBI diagnosis and intracellular imaging have been studied using the multifunctional DNA–AgNCs.

Cell mimetic liposomal nanocarriers for tailored delivery of vascular therapeutics.

Liposomal delivery systems (LDSs) have been at the forefront of medicinal nanotechnology for over three decades. Increasing LDS association to target cells and cargo delivery is crucial to bolstering overall nanodrug efficacy. Our laboratory aims to develop LDSs for molecular therapeutics aimed at vascular pathology. We have previously established a liposome platform that is an effective delivery system for RNA interference in vascular cell types by using polyethylene glycol (PEG) decorated liposomes bearing an octa-arginine (R8) cell penetrating peptide (CPP). Further tailoring liposome membranes to mimic vascular cell membrane lipid constituents may be a promising strategy for increasing cargo delivery. Here we aimed to develop liposomal formulations that could make use of diacylglycerol (DAG) and phosphatidylserine (PS), naturally occurring lipid species that are known to influence vascular cell function, as a facile and efficient means to increase nanodrug efficacy without compromising clinical viability. We investigated the ability of DAG and PS to amplify the cellular uptake of our previously established LDS platform loaded with small interfering ribonucleic acid (siRNA) cargo. Cellular fluorescence microscopy experiments were performed in conjunction with quantitative cell association assays and cytotoxicity assays to analyze the effect of DAG/PS on the differential delivery of fluorescently-tagged liposomes to vascular smooth muscle cells (VSMCs) and vascular endothelial cells (VECs) and on liposomal-mediated toxicity. In these studies, significant, dose-dependent increases in association to target cells were observed, as well as cell-type specific effects on cell viability. The stability and encapsulation-efficiency of the DAG/PS-modified LDSs were analyzed by standard nanoparticle characterization methods, and siRNA transfection efficacy was quantified to gauge delivery potential as a function of DAG/PS modification. Our results suggest that the signaling lipids tested here imbue our LDS architectures with increased therapeutic potential, without compromising stability, encapsulation efficiency, or biocompatibility, thus presenting a natural strategy to increase nanodrug efficacy and specificity.

A flow cytometric analysis of macrophage- nanoparticle interactions in vitro: induction of altered Toll-like receptor expression.

BackgroundNanoparticles exhibit unique physiochemical characteristics that provide the basis for their utilization. The diversity of potential and actual applications compels a thorough understanding regarding the consequences of their containment within the cellular environment.PurposeThis paper presents a flow cytometric examination of the biologic effects associated with the internalization of citrate-buffered silver (Ag) nanoparticles (NP) by the murine macrophage cell line, RAW264.7.Materials and methodsCells were cultured with varying concentrations of citrate-buffered Ag nanoparticle and analyzed for changes in cellular volume, fluorescence emissions, and surface receptor expression.ResultsNotable changes in side scatter (SSC) signal occurred following the phagocytosis of citrate-buffered Ag NP representative of the 10 nm, 50 nm, and 100 nm particle size by cultured RAW 264.7 cells. A characteristic associated with the internalization of all the citrated Ag NP sizes tested, was the detection of emitted infra-red and near-infrared wavelength emissions. This characteristic consistently permitted the detection of 10 nm, 50 nm, and 100 nm Ag NP particles internalized within the RAW cells by flow cytometry. A functional distinction between monocyte subsets within the RAW 264.7 cell line was noted as Ag NP are taken up by the F4/80+ subset of cells within the culture. Further, the internalization of Ag NP by the cells resulted in an increased cell surface expression of the Toll-like receptor (TLR) 3, but not TLR4.ConclusionTaken together, these results implicate the more mature macrophage in the ingestion of Ag NP; and an influence upon at least one of the Toll receptors present in macrophages following exposure to Ag NP. Further, our flow cytometric approach presents a potentially viable detection method for the identification of occult Ag NP material using an indicator cell line.

Automated high-throughput light-sheet fluorescence microscopy of larval zebrafish.

Light sheet fluorescence microscopy enables fast, minimally phototoxic, three-dimensional imaging of live specimens, but is currently limited by low throughput and tedious sample preparation. Here, we describe an automated high-throughput light sheet fluorescence microscope in which specimens are positioned by and imaged within a fluidic system integrated with the sheet excitation and detection optics. We demonstrate the ability of the instrument to rapidly examine live specimens with minimal manual intervention by imaging fluorescent neutrophils over a nearly 0.3 mm3 volume in dozens of larval zebrafish. In addition to revealing considerable inter-individual variability in neutrophil number, known previously from labor-intensive methods, three-dimensional imaging allows assessment of the correlation between the bulk measure of total cellular fluorescence and the spatially resolved measure of actual neutrophil number per animal. We suggest that our simple experimental design should considerably expand the scope and impact of light sheet imaging in the life sciences.

Poly(ε-caprolactone) modified organic dyes nanoparticles for noninvasive long term fluorescence imaging

Application of organic dyes is limited in biomedical fields due to the rapid self-quenching, poor stability and water solubility. In this work, polymer modified organic dyes is developed through the dyes initiating polymerization. The polymer length is studied by tuning the amount of monomer. With an optimal molecule weight of the polymer, the π-π stacking from π-conjugated organic fluorescent dyes and fluorescence quenching are inhibited, resulting in an enhancement of fluorescence intensity and photostability. Nanoparticles are further fabricated to be used for cell uptake based on the optimized organic dyes. Then, long term cellular fluorescence imaging is realized. This work highlights the potential of polymer modification to improve the performance of organic dyes and expand their applications.

82. Disulfiram inhibits placental sFLT-1 secretion

Introduction Preeclampsia is associated with elevated placental secretion of the anti-angiogenic factor sFLT-1. Surprisingly, little is understood about its regulation, identifying such mechanisms may uncover therapeutic leads. Objectives Our objective was to determine the effects of disulfiram, a 20S subunit proteasome inhibitor, on placental secretion of sFLT-1 and endothelial dysfunction. Methods Primary trophoblast were isolated from normotensive term placenta, treated with disulfiram and mRNA expression of sFLT-1 variants and protein secretion assessed. To assess the effects of disulfiram on the 20S subunit of the proteasome, primary trophoblast were treated with disulfiram in the presence of Suc-LLVY-AMC fluorogenic substrate. Next, we investigated the effect of disulfiram on endothelial dysfunction using isolated primary human umbilical vein endothelial cells (HUVECs) treated with 5% preeclamptic serum +/− disulfiram. The effect of disulfiram on markers of endothelial dysfunction were measured via qRT-PCR for vascular cell adhesion molecule-1 (VCAM-1) and adhesion of fluorescently labelled peripheral blood mononuclear cells (PBMCs) to HUVECs. Results Disulfiram significantly reduced mRNA expression of the sFLT-1 variants, sFLT-1-i13 and sFLT-e15a. This translated into a significant and dose dependent reduction in the protein secretion of sFLT-1. In primary trophoblast disulfiram did not inhibit the 20S subunit of the proteasome, evidenced by no change in cellular fluorescence following addition of Suc-LLVY-AMC. Treating primary HUVECs with serum from preeclamptic women induced endothelial dysfunction with significantly increased mRNA expression of VCAM-1 as well as the adhesion of PBMCs to HUVECs. Disulfiram reduced VCAM-1, with expression reduced below control levels, however, did not alter the adhesion of PBMCs to primary HUVECs. Conclusions We have identified disulfiram to quench placental sFLT-1 secretion via a mechanism independent of inhibiting the 20S subunit of the proteasome. Understanding of the mechanisms by which disulfiram inhibits sFLT-1 secretion may assist in identifying therapeutic targets. Interestingly, disulfiram also reduced markers of endothelial dysfunction.