Acute Monocytic Leukemia Cell Line Research Articles

High glucose condition aggravates inflammatory response induced by Porphyromonas gingivalis in THP-1 macrophages via autophagy inhibition

BackgroundPorphyromonase gingivalis (P. gingivalis) is a type of bacteria that causes periodontitis, which is strongly correlated with systemic diseases such as diabetes. However, the effect of hyperglycemia on periodontitis are unclear. The present study examined the effects of high glucose levels on the response to P. gingivalis infection.ResultsThe expression of P. gingivalis-induced interleukin-1β (IL-1β) and inflammasomes increased as the glucose concentration increased. High glucose conditions suppressed P. gingivalis–induced autophagy in human acute monocytic leukemia cell line (THP-1) macrophages. Zingerone increased autophagy and alleviated P. gingivalis-induced inflammatory response in THP-1 macrophages under high glucose conditions. In addition, P. gingivalis- induced inflammation in bone marrow-derived macrophages of diabetic mice was higher than in wild-type mice, but a zingerone treatment decreased the levels. Alveolar bone loss due to a P. gingivalis infection was significantly higher in diabetic mice than in wild-type mice.ConclusionsHigh-glucose conditions aggravated the inflammatory response to P. gingivalis infection by suppressing of autophagy, suggesting that autophagy induction could potentially to treat periodontitis in diabetes. Zingerone has potential use as a treatment for periodontal inflammation induced by P. gingivalis in diabetes patients.

Esculin-Induced Apoptosis and Suppression of Leukemia Surface Markers in HL-60 and THP-1 Cells: A Potential Selective Anticancer Agent

Esculin, a natural coumarin compound primarily derived from Cortex fraxini, is known for its anti-inflammatory and antioxidant properties. Leukemia, a type of hematological cancer, is characterized by the uncontrolled proliferation of white blood cells and has high mortality rates. In this study, we aimed to investigate the potential anticancer effects of esculin (Esculetin-6-Glucoside) on leukemia cell lines, focusing on how this compound could be utilized in cancer treatment through apoptotic pathways. Our experiments used acute promyelocytic leukemia (HL-60) and acute monocytic leukemia (THP-1) cell lines. Cancer cell counting and viability analyses were conducted using the MTS assay(5-(3-carboxymethoxyphenyl)-2-(4,5-dimethylthiazol)-3-(4-sulfophenyl) tetrazolium inner salt assay). Apoptosis was assessed using FITC-labeled Annexin V and propidium iodide. Caspase-3 activation, cytochrome C release, leukemia cell surface markers, and mitochondrial membrane potential (MMP) were analyzed via flow cytometry. Our results demonstrated that esculin can induce apoptosis in leukemia cell lines. Additionally, leukemia surface markers post-treatment were statistically significantly reduced post-treatment in both cell lines. HL-60 and THP-1 cells exhibited different cellular responses in terms of MMP, Caspase-3, and Cytochrome C activities; HL-60 cells were more resistant to esculin treatment, while THP-1 cells were more sensitive. These findings suggest that esculin could become a potential agent in cancer treatment by targeting apoptotic pathways. However, more in vivo studies and preclinical modeling are needed to understand the anticancer effects of esculin fully. Evaluating its efficacy against different cancer types could further expand the therapeutic potential of this compound.

Selection and Characterization of a DNA Aptamer Recognizing High Mobility Group Box 1 Protein (HMGB1) and Enhancing Its Pro-inflammatory Activity

Background: High mobility group box 1 (HMGB1) plays an essential role in various pathological conditions, including inflammation, fibrosis, autoimmune diseases, and carcinogenesis. The quantification of HMGB1 in body fluids holds promise for clinical applications. Objectives: This study aimed to isolate high-affinity single-stranded DNA (ssDNA) aptamers that target HMGB1. Methods: In this study, ssDNA aptamers were selected using Systematic Evolution of Ligands by Exponential Enrichment (SELEX). The affinity and specificity of the aptamers were evaluated through South-Western blot analysis, enzyme-linked aptamer sorbent assay (ELASA), and aptamer-based histochemistry staining. The impact of the aptamers on the biological activity of HMGB1 was tested in the human acute monocytic leukemia cell line, THP-1. Results: An aptamer (H-ap25, dissociation constant = 8.20 ± 0.53 nmol/L) with high affinity for the HMGB1 B box was generated. Further experiments verified that H-ap25 can be used to detect HMGB1 in South-Western blot analysis, ELASA, and aptamer-based histochemistry staining. Moreover, H-ap25 significantly augmented HMGB1-induced expression of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, Toll-like receptor 9 (TLR9), and activation of NF-κB in THP-1 cells. Conclusions: Our results demonstrated that H-ap25 can be used both as an enhancer of HMGB1 and as a probe in research.

Ternary Copper(II) Coordination Compounds with Nonpolar Amino Acids and 2,2′-Bipyridine: Monomers vs. Polymers

Reactions of copper(II) sulfate with 2,2′-bipyridine (bipy) and amino acids with nonpolar side chains (l-alanine (HAla), l-valine (HVal), or l-phenylalanine (HPhe)) were investigated under different solution-based and mechanochemical methods. Five new ternary coordination compounds were obtained by a solution-based synthesis and three of them additionally by the liquid-assisted mechanochemical method: {[Cu(μ-l-Ala)(H2O)(bipy)]2SO4·2H2O}n (1a·2H2O), {[Cu(μ-l-Ala)(H2O)(bipy)][Cu(l-Ala)(H2O)(bipy)]SO4·2.5H2O}n (1b·2.5H2O), {[Cu(μ-l-Val)(H2O)(bipy)][Cu(l-Val)(H2O)(bipy)]3(SO4)2·4H2O}n (2·4H2O), [Cu(l-Phe)(H2O)(bipy)][Cu(l-Phe)(SO4)(bipy)]∙8H2O (3·8H2O), and [Cu(l-Phe)(H2O)(bipy)][Cu(l-Phe)(SO4)(bipy)]∙9H2O (3·9H2O). The compounds were characterized by single-crystal and powder X-ray diffraction, infrared spectroscopy, and a thermal analysis. Structural studies revealed two structural types, monomeric in 3·8H2O and 3·9H2O, polymeric architectures in 1a·2H2O, and mixed structures (monomeric and polymeric) in 1b·2.5H2O and 2·4H2O. The copper(II) ion is either pentacoordinated or hexacoordinated, with an observed Jahn–Teller effect. The crystal structures are based on an intensive network of hydrogen bonds and π interactions. 1a·2H2O and 2·4H2O showed substantial in vitro antiproliferative activity toward human hepatocellular carcinoma (HepG2) and moderate activity toward human acute monocytic leukemia cell lines (THP-1).

The dual role of FSP1 in programmed cell death: resisting ferroptosis in the cell membrane and promoting necroptosis in the nucleus of THP-1 cells

BackgroundAcute monocytic leukemia-M5 (AML-M5) remains a challenging disease due to its high morbidity and poor prognosis. In addition to the evidence mentioned earlier, several studies have shown that programmed cell death (PCD) serves a critical function in treatment of AML-M5. However, the role and relationship between ferroptosis and necroptosis in AML-M5 remains unclear.MethodsTHP-1 cells were mainly treated with Erastin and IMP-366. The changes of ferroptosis and necroptosis levels were detected by CCK-8, western blot, quantitative real-time PCR, and electron microscopy. Flow cytometry was applied to detect the ROS and lipid ROS levels. MDA, 4-HNE, GSH and GSSG were assessed by ELISA kits. Intracellular distribution of FSP1 was studied by immunofluorescent staining and western blot.ResultsThe addition of the myristoylation inhibitor IMP-366 to erastin-treated acute monocytic leukemia cell line THP-1 cell not only resulted in greater susceptibility to ferroptosis characterized by lipid peroxidation, glutathione (GSH) depletion and mitochondrial shrinkage, as the FSP1 position on membrane was inhibited, but also increased p-RIPK1 and p-MLKL protein expression, as well as a decrease in caspase-8 expression, and triggered the characteristic necroptosis phenomena, including cytoplasmic translucency, mitochondrial swelling, membranous fractures by FSP1 migration into the nucleus via binding importin α2. It is interesting to note that ferroptosis inhibitor fer-1 reversed necroptosis.ConclusionWe demonstrated that inhibition of myristoylation by IMP-366 is capable of switching ferroptosis and ferroptosis-dependent necroptosis in THP-1 cells. In these findings, FSP1-mediated ferroptosis and necroptosis are described as alternative mechanisms of PCD of THP-1 cells, providing potential therapeutic strategies and targets for AML-M5.

Ethnobotanical survey and biological activities of plants used for cancer treatment in traditional Senegalese medicine

Female breast cancer is known to be one of the leading causes of death in Senegal. In Senegal, the absence of a national cancer control program, the lack of specialized infrastructure and qualified human resources and the exorbitant cost of care have contributed to the extensive use of traditional medecine, particularly in rural areas. This study aims to inventory the medicinal plants used by these healers and to assess the cytotoxic and antioxidant activities of the most widely used one. Data on healers and their use practices and information on plants were collected through the administration of a structured questionnaire. Based on their citation frequencies during the survey, Antiaris Africana Engler, Hymenocardia Acida Tul. and Halouf Halal (local name) were selected for chemical and biological studies. Their hydroalcoholic extracts were analyzed in terms of antioxidant capacity and cytotoxic effects, again, in the human cancer cell line. The study revealed a total of 65 medicinal plants belonging to 35 different families. The plant parts used by traditional healers are leaves (63.89%), roots (11.11%), bark (15.28%), fruits (2.78%), and others (6.94%). Generally, herbal medicine is prepared as a powder and mixed with water by maceration (55.38%) and administered orally. A. Africana ranked first with a citation frequency of 5.7% and its hydroalcoholic extract had the highest antioxidant activity in TEAC (6533.64±7 μmol ET/g dry plant) and in ORAC (3745.17±4.8 μmol ET/g dry plant) followed by H. Acida in TEAC (3115.6±145 μmol ET/g dry plant) and in ORAC (4105.29±872 μmol ET/g dry plant). The hydroalcoholic extract of A. Africana exhibited the highest cytotoxic activity in MCF-7 (Human mammary) and THP-1 (Human acute monocytic leukemia cell line) but had low activity against HTC-116 (Human carcinoma colorectal) and A-375 (Human skin malignant melanoma). The percentages of proapoptotic cells were, respectively, 68.85±6.22, 58.1±1.90 and 48.58±1.4%. These results provide scientific support for the traditional use of medicinal plants in cancer treatment and constitute a database for biological screening to isolate cytotoxic plant-based molecules.

Rapamycin increases leukemia cell sensitivity to chemotherapy by regulating mTORC1 pathway-mediated apoptosis and autophagy.

This study investigated the effect of rapamycin alone and in combination with chemotherapy (doxorubicin and cytarabine) on AML. Human acute monocytic leukemia cell line SHI-1 and NPG AML model mice created by intravenous injection of SHI-1 cell were treated with rapamycin, chemotherapy, or rapamycin plus chemotherapy. Analysis by cell counting kit-8, western blot, flow cytometry, and immunohistochemistry was performed, and results suggested that both rapamycin and chemotherapy inhibited proliferation of SHI-1 cells both in vitro and in vivo, suppressed neoplasm growth in vivo, and promoted survival of NPG AML mice. The antitumor effect of rapamycin plus chemotherapy was better than that of rapamycin alone and chemotherapy alone. In addition, western blot results demonstrated that rapamycin inhibited the phosphorylation of mTOR downstream targets 4EBP1 and S6K1 in SHI-1 cells, and increased the pro-apoptosis-related protein Bax and autophagy-associated proteins Beclin-1, LC3B-II, and ATG5 while reducing the anti-apoptosis-related protein Bcl-2. In conclusion, the results of this study indicate that rapamycin acts synergistically with doxorubicin and cytarabine in AML treatment, and its underlying mechanism might be associated with mTORC1 pathway-mediated apoptosis and autophagy.

Ribonucleic Acid Sequencing Reveals the Upregulation and Resolution of Inflammation and Extracellular Matrix Remodeling in Lidocaine-Treated Human Acute Monocytic Leukemia Cell Line THP-1.

Lidocaine, a local anesthetic widely used in dentistry, is esteemed for its efficacy and safety. Recent research reveals its additional role in modulating the immune system, and particularly in reducing inflammation crucial for protecting tooth-supporting tissues. Notably, monocytes and macrophages, essential cellular components overseeing various physiological and pathological processes, stand as potential mediators of lidocaine's effects. Therefore, this study aimed to investigate how lidocaine influences cell behavior using RNA sequencing. To investigate the effect of lidocaine on THP-1 cells' behavior, we performed an MTT assay and RNA-Seq along with qPCR analyses to evaluate the transcriptomic and proteomic changes in THP-1 cells. Our results showed that a high dose of lidocaine (>1 mM) had a significant cytotoxic effect on THP-1 cells. However, a lidocaine dose lower than 0.5 mM induced a mixed anti-inflammatory profile by significantly upregulating tissue remodeling (GDF15, FGF7, HGF, COL4A3, COL8A2, LAMB2, LAMC2, PDGFRA, and VEGFA) and through the resolution of inflammation (Cpeb4, Socs1, Socs2, Socs3, Dusp1, Tnfaip3, and Gata3) gene cassettes. This study explores the effect of lidocaine on the THP-1 in the M2-like healing phenotype and provides potential applications of lidocaine's therapeutic effectiveness in dental tissue repair.

Biological Effects of Small Sized Graphene Oxide Nanosheets on Human Leukocytes.

Since the discovery of graphene, there has been a wide range of the literature dealing with its versatile structure and easy binding of biomolecules as well as its large loading capacity. In the emerging field of immunotherapy, graphene and its derivatives have potential uses as drug delivery platforms directly into tumour sites or as adjuvants in cancer vaccines, as they are internalized by monocytes which in turn may activate adaptive anti-tumoral immune responses. In this study, we expose cells of the innate immune system and a human acute monocytic leukemia cell line (THP-1) to low doses of small-sized GO nanosheets functionalized with bovine serum albumin (BSA) and fluorescein isothiocyanate (FITC), to study their acute response after internalization. We show by flow cytometry, uptake in cells of GO-BSA-FITC reaches 80% and cell viability and ROS production are both unaffected by exposure to nanoparticles. On the contrary, GO-BSA nanosheets seem to have an inhibitory effect on ROS production, probably due to their antioxidant properties. We also provided results on chemotaxis of macrophages derived from peripheral blood monocytes treated with GO-BSA. In conclusion, we showed the size of nanosheets, the concentration used and the degree of functionalization were important factors for biocompatibility of GO in immune cells. Its low cytotoxicity and high adaptability to the cells of the innate immune system make it a good candidate for deployment in immunotherapy, in particular for delivering protein antigens to monocytes which activate adaptive immunity.

Streptolysin S induces proinflammatory cytokine expression in calcium ion-influx-dependent manner

Anginosus group streptococci (AGS) are opportunistic pathogens that reside in the human oral cavity. The β-hemolytic strains of Streptococcus anginosus subsp. anginosus (SAA) produce streptolysin S (SLS), a streptococcal peptide hemolysin. In recent clinical scenarios, AGS, including this species, have frequently been isolated from infections and disorders beyond those in the oral cavity. Consequently, investigating this situation will reveal the potential pathogenicity of AGS to ectopic infections in humans. However, the precise mechanism underlying the cellular response induced by secreted SLS and its relevance to the pathogenicity of AGS strains remain largely unknown. This study aims to elucidate the mechanism underlying the host cellular response of the human acute monocytic leukemia cell line THP-1 to secreted SLS. In THP-1 cells incubated with the culture supernatant of β-hemolytic SAA containing SLS as the sole cytotoxic factor, increased Ca2+ influx and elevated expression of proinflammatory cytokines were observed. Significantly reduced expression of SLS-dependent upregulated cytokine genes under Ca2+-chelating conditions suggests that Ca2+ influx triggers SLS-dependent cellular responses. Furthermore, SLS-dependent enhanced expression of IL-8 was also implicated in the activation of extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinase (MAPK) signaling pathways. The findings presented in this study are crucial for a comprehensive understanding of the real pathogenicity of SLS-producing β-hemolytic AGS in the latest clinical situations.

Rapid cellular uptake of citrate-coated iron oxide nanoparticles unaffected by cell-surface glycosaminoglycans.

Citrate-coated iron oxide nanoparticles, specifically Synomag®-COOH (SynC), are promising tracers in magnetic particle imaging (MPI) due to their high magnetic moments and rapid cellular uptake. The mechanisms driving efficient SynC uptake remain unclear. Previous observations suggest a role of the extracellular glycocalyx during nanoparticle uptake. Here, we ascertain whether the cell-surface glycosaminoglycans (GAGs) regulate the uptake of SynC. Using transmission electron microscopy (TEM), we visualized SynC uptake by THP-1 cells, a human acute monocytic leukemia cell line. We investigated the interaction of SynC with GAGs in living cells using click-chemistry-based labeling. Upon treating THP-1 cells with chondroitinase or hyaluronidase and with a xylosyltransferase-deficient cell line, we quantified SynC uptake and measured interactions of SynC with cells in real time using magnetic particle spectroscopy (MPS). The THP-1 cell membrane engulfed or formed extensions around SynC, indicating uptake through pinocytosis and phagocytosis. We measured an increased MPS signal of SynC within seconds of cell contact, suggesting an interaction with extracellular components like the glycocalyx. Upon adding SynC to THP-1 cells, we could not observe disruption of fluorescently labeled GAGs or an enhanced intracellular fluorescence, implying that SynC does not accelerate the turnover of GAGs by binding. Lack of chondroitin sulfate, heparan sulfate, and hyaluronic acid did not affect the rapid magnetic behavior increase of SynC upon cell contact. Accordingly, we measured no significant differences in SynC uptake between wild type cells and our GAG-deficient models. These findings suggest that GAGs act as a permeable bandpass for SynC nanoparticles with a minor negative surface charge of -13.8 mV. This finding has significant implications for MPI-based cell tracking because it facilitates efficient tracking of cell types that lack a strong repulsion by cell-surface GAGs. It will be crucial to investigate whether the rapid uptake of SynC is cell-type specific and influenced by different extracellular matrix compositions.

Photothermal Prussian blue nanoparticles generate potent multi-targeted tumor-specific T cells as an adoptive cell therapy.

Prussian blue nanoparticle-based photothermal therapy (PBNP-PTT) is an effective tumor treatment capable of eliciting an antitumor immune response. Motivated by the ability of PBNP-PTT to potentiate endogenous immune responses, we recently demonstrated that PBNP-PTT could be used ex vivo to generate tumor-specific T cells against glioblastoma (GBM) cell lines as an adoptive T cell therapy (ATCT). In this study, we further developed this promising T cell development platform. First, we assessed the phenotype and function of T cells generated using PBNP-PTT. We observed that PBNP-PTT facilitated CD8+ T cell expansion from healthy donor PBMCs that secreted IFNγ and TNFα and upregulated CD107a in response to engagement with target U87 cells, suggesting specific antitumor T cell activation and degranulation. Further, CD8+ effector and effector memory T cell populations significantly expanded after co-culture with U87 cells, consistent with tumor-specific effector responses. In orthotopically implanted U87 GBM tumors in vivo, PBNP-PTT-derived T cells effectively reduced U87 tumor growth and generated long-term survival in >80% of tumor-bearing mice by Day 100, compared to 0% of mice treated with PBS, non-specific T cells, or T cells expanded from lysed U87 cells, demonstrating an enhanced antitumor efficacy of this ATCT platform. Finally, we tested the generalizability of our approach by generating T cells targeting medulloblastoma (D556), breast cancer (MDA-MB-231), neuroblastoma (SH-SY5Y), and acute monocytic leukemia (THP-1) cell lines. The resulting T cells secreted IFNγ and exerted increased tumor-specific cytolytic function relative to controls, demonstrating the versatility of PBNP-PTT in generating tumor-specific T cells for ATCT.

Influence of Microbiota-Related Metabolites Associated with Inflammation and Sepsis on the Peroxidase Activity of Cyclooxygenase in Healthy Human Monocytes and Acute Monocytic Leukemia Cells.

The human microbiota produces metabolites that can enter the bloodstream and exert systemic effects on various functions in both healthy and pathological states. We have studied the participation of microbiota-related metabolites in bacterial infection by examining their influence on the activity of cyclooxygenase (COX) as a key enzyme of inflammation. The influence of aromatic microbial metabolites, derivatives of phenylalanine (phenylpropionic acid, PPA), tyrosine (4-hydroxyphenyllactic acid, HPLA), and tryptophan (indolacetic acids, IAA), the concentrations of which in the blood change notably during sepsis, was evaluated. Also, the effect of itaconic acid (ITA) was studied, which is formed in macrophages under the action of bacterial lipopolysaccharides (LPS) and appears in the blood in the early stages of infection. Metabiotic acetyl phosphate (AcP) as a strong acetylating agent was also tested. The activity of COX was measured via the TMPD oxidation colorimetric assay using the commercial pure enzyme, cultured healthy monocytes, and the human acute monocytic leukemia cell line THP-1. All metabolites in the concentration range of 100-500 μM lowered the activity of COX. The most pronounced inhibition was observed on the commercial pure enzyme, reaching up to 40% in the presence of AcP and 20-30% in the presence of the other metabolites. On cell lysates, the effect of metabolites was preserved, although it significantly decreased, probably due to their interaction with other targets subject to redox-dependent and acetylation processes. The possible contribution of the redox-dependent action of microbial metabolites was confirmed by assessing the activity of the enzyme in the presence of thiol reagents and in model conditions, when the COX-formed peroxy intermediate was replaced with tert-butyl hydroperoxide (TBH). The data show the involvement of the microbial metabolites in the regulation of COX activity, probably due to their influence on the peroxidase activity of the enzyme.

Anti-inflammatory effects of cold atmospheric plasma irradiation on the THP-1 human acute monocytic leukemia cell line.

Cold atmospheric plasma (CAP) has been studied and clinically applied to treat chronic wounds, cancer, periodontitis, and other diseases. CAP exerts cytotoxic, bactericidal, cell-proliferative, and anti-inflammatory effects on living tissues by generating reactive species. Therefore, CAP holds promise as a treatment for diseases involving chronic inflammation and bacterial infections. However, the cellular mechanisms underlying these anti-inflammatory effects of CAP are still unclear. Thus, this study aimed to elucidate the anti-inflammatory mechanisms of CAP in vitro. The human acute monocytic leukemia cell line, THP-1, was stimulated with lipopolysaccharide and irradiated with CAP, and the cytotoxic effects of CAP were evaluated. Time-course differentiation of gene expression was analyzed, and key transcription factors were identified via transcriptome analysis. Additionally, the nuclear localization of the CAP-induced transcription factor was examined using western blotting. The results indicated that CAP showed no cytotoxic effects after less than 70 s of irradiation and significantly inhibited interleukin 6 (IL6) expression after more than 40 s of irradiation. Transcriptome analysis revealed many differentially expressed genes (DEGs) following CAP irradiation at all time points. Cluster analysis classified the DEGs into four distinct groups, each with time-dependent characteristics. Gene ontology and gene set enrichment analyses revealed CAP-induced suppression of IL6 production, other inflammatory responses, and the expression of genes related to major histocompatibility complex (MHC) class II. Transcription factor analysis suggested that nuclear factor erythroid 2-related factor 2 (NRF2), which suppresses intracellular oxidative stress, is the most activated transcription factor. Contrarily, regulatory factor X5, which regulates MHC class II expression, is the most suppressed transcription factor. Western blotting revealed the nuclear localization of NRF2 following CAP irradiation. These data suggest that CAP suppresses the inflammatory response, possibly by promoting NRF2 nuclear translocation.

Optimization and characterization of antileukemic l-asparaginase produced by Fusarium solani endophyte

l-asparaginase is an antileukemic enzyme that hydrolyzes l-asparagine into l-aspartic acid and ammonia, causing cell starvation and apoptosis in susceptible leukemic cell populations. Currently, l-asparaginase obtained from bacterial sources is constrained by several issues, including lesser productivity, stability, selectivity, and higher toxicity. The goal of this study is to provide fungal l-asparaginase with in-vitro effectiveness towards different human carcinomas. l-asparaginase from endophytic Fusarium solani (Gene Bank accession number MW209717) isolated from the roots of the medicinal plant Hedera helix L. was characterized and optimized experimentally for maximum l-asparaginase production in addition to evaluating its subsequent cytotoxicity towards acute monocytic leukemia and human skin fibroblast cell lines. The enzyme production was maximized using potato dextrose media (15.44 IU/ml/hr) at the 5th and 6th days of fermentation with incubation temperature 30 °C, 3% asparagine, 150–180 rpm agitation rate and a 250 ml flask. Enzyme characterization studies revealed that the enzyme maintained its thermal stability with temperatures up to 60 °C. However, its optimal activity was achieved at 35 °C. On measuring the enzymatic activity at various temperatures and different pH, maximum enzyme activity was recorded at 40 °C and pH 8 using 0.1 M asparagine concentration. Results also revealed promising cytotoxic activity against acute monocytic leukemia with IC50 = 3.66 µg/ml and low cytotoxicity against tested normal human skin fibroblast cell line which suggested that it might have selective toxicity, and consequently it could be used as a less toxic alternative to the current formulations.

Celastrol attenuates human parvovirus B19 NS1‑induced NLRP3 inflammasome activation in macrophages.

Human parvovirus B19 (B19V) has been strongly associated with a variety of inflammatory disorders, such as rheumatoid arthritis (RA), inflammatory bowel disease and systemic lupus erythematosus. Non‑structural protein 1 (NS1) of B19V has been demonstrated to play essential roles in the pathological processes of B19V infection due to its regulatory properties on inflammatory cytokines. Celastrol, a quinone methide isolated from Tripterygiumwilfordii, has displayed substantial potential in treating inflammatory diseases, such as psoriasis and RA. However, little is known about the effects of celastrol on B19V NS1‑induced inflammation. Therefore, cell viability assay, migration assay, phagocytosis analysis, zymography assay, ELISA and immunoblotting were conducted to verify the influences of celastrol on macrophages. The present study reported the attenuating effects of celastrol on B19V NS1‑induced inflammatory responses in macrophages derived from human acute monocytic leukemia cell lines, U937 and THP‑1. Although the migration was not significantly decreased by celastrol in both U937 and THP‑1 macrophages, significantly decreased viability, migration and phagocytosis were detected in both B19V NS1‑activated U937 and THP‑1 macrophages in the presence of celastrol. Additionally, celastrol significantly decreased MMP‑9 activity and the levels of inflammatory cytokines, including IL‑6, TNF‑α and IL‑1β, in B19V NS1‑activated U937 and THP‑1 cells. Notably, significantly decreased levels of NLR family pyrin domain‑containing 3, apoptosis‑associated speck‑like, caspase‑1 and IL‑18 proteins were observed in both B19V NS1‑activated U937 and THP‑1 cells in the presence of celastrol, indicating the involvement of the inflammasome pathway. To the best of our knowledge, the present study is the first to report on the attenuating effects of celastrol on B19V NS1‑induced inflammatory responses in macrophages, suggesting a therapeutic role for celastrol in B19V NS1‑related inflammatory diseases.

Evaluating the Antioxidant Properties of the Ancient-Crop Tef (Eragrostis tef) Grain Extracts in THP-1 Monocytes.

Tef (Eragrostis tef) is an orphan crop that is widely grown in East Africa, primarily in Ethiopia as a staple crop. It is becoming popular in the Western world owing to its nutritious and gluten-free grains and the forage quality of its biomass. Tef is also considered to have a high antioxidant capacity based on cell-free studies. However, the antioxidant activity of tef has never been validated using a physiologically relevant cell model. The purpose of this study was to investigate the antioxidant capacity of tef grain extracts using a mammalian cell model. We hypothesized that the tef grain extracts are capable of modulating the cellular antioxidant response via the modulation of glutathione (GSH) biosynthetic pathways. Therefore, we evaluated the antioxidant activity of purified tef grain extracts in the human acute monocytic leukemia (THP-1) cell line. Our findings revealed that the organic fraction of grain extracts increased the cellular GSH level, which was more evident for brown-colored tef than the ivory variety. Moreover, a brown-tef fraction increased the expressions of GSH-pathway genes, including γ-glutamate cysteine ligase catalytic (GCLC) and modifier (GCLM) subunits and glutathione reductase (GR), an enzyme that plays a key role in GSH biosynthesis, suggesting that tef extracts may modulate GSH metabolism. Several compounds were uniquely identified via mass spectrometry (MS) in GSH-modulating brown-tef samples, including 4-oxo-β-apo-13-carotenone, γ-linolenic acid (methyl ester), 4,4'-(2,3-dimethyl-1,4-butanediyl)bis-phenol (also referred to as 8,8'-lignan-4,4'-diol), and (3β)-3-[[2-[4-(Acetylamino)phenoxy]acetyl]oxy]olean-12-en-28-oic acid. Tef possesses antioxidant activity due to the presence of phytochemicals that can act as direct antioxidants, as well as modulators of antioxidant-response genes, indicating its potential role in alleviating diseases triggered by oxidative stresses. To the best of our knowledge, this is the first report revealing the antioxidant ability of tef extracts in a physiologically relevant human cell model.

Synthesis and evaluation of multitarget new 2-aminothiazole derivatives as potential anti-Alzheimer's agents.

In this study, two diverse series of 2-aminothiazole-based multitarget compounds, one propenamide and the other propanamide derivatives, were designed and synthesized. Subsequently, their anticholinesterease and antioxidant (ORAC) activities were tested. Among them, compound 3e was the most potent acetylcholinesterase (AChE) inhibitor (AChE IC50 = 0.5 μM, butyrylcholinesterase [BChE] IC50 = 14.7 μM) and compound 9e was the most potent BChE inhibitor (AChE IC50 = 3.13 μM, BChE IC50 = 0.9 μM). Kinetic experiments showed that both compounds were mixed-type inhibitors. According to the anticholinesterease activity results, five compounds (3e, 4e, 5e, 9d, and 9e) were selected for further activity studies, all of which are dual cholinesterase inhibitors. Then, selected compounds were investigated in terms of their metal chelation activity. Moreover, their neuroprotective effects against H2 O2 -induced damage in the PC12 cell line were evaluated at 10 μM and the results showed that the neuroprotective effect of 3e was 53% compared with the reference ferulic acid (77%). 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) results of selected compounds revealed that the compounds were noncytotoxic. Additionally, 3e was more effective in reducing lipopolysaccharides-induced interleukin-1β (IL-1β), IL-6, tumor necrosis factor-α (TNF-α), and nitric oxide (NO) production in the human monocyte derived from patient with acute monocytic leukemia cell line compared with other selected compounds. Finally, a molecular docking study was also performed.

Insights into the Hippocampus Proteomics Reveal Epigenetic Properties of Walnut-Derived Peptides in a Low-Grade Neuroinflammation Model.

Epigenetic mechanisms that dysregulate gene expressions may play a significant role in the development of neurological disorders. However, whether peptides can modulate epigenetic mechanisms remains elusive. This work aimed to investigate the impact of pretreatment with walnut-derived peptides─WHP and YVLLPSPK─on DNA methylation in a low-grade neuroinflammation model. The enriched KEGG pathways included oxidative phosphorylation, riboflavin metabolism, ribosome, and pyrimidine metabolism, which are associated with methylation modification by oral administration of YVLLPSPK in mice with scopolamine-induced cognitive deficits. Furthermore, when THP-1 cells (human acute monocytic leukemia cell line) were exposed to lipopolysaccharide (LPS)-induced inflammation responses, both WHP and YVLLPSPK markedly inhibited the level of Il-6 to 2.05 ± 0.76 and 1.29 ± 0.19 (p < 0.05) and also declined the mRNA expression of Mcp-1 to 1.64 ± 0.02 and 3.29 ± 1.21 (p < 0.01), respectively. Meanwhile, YVLLPSPK decreased the activities of DNA methyltransferases (DNMTs) to 1.03 ± 0.02 and 1.20 ± 0.31 (p < 0.05) based on Dnmt3b and Tet2, respectively. The results indicated that YVLLPSPK modulated DNA methylation in embryonic and neural precursor cells in creating new methylation patterns. Further trials are needed to assess the mechanisms underlying DNA methylation changes through peptides in the pathophysiology of neurological disorders.

281 Fc gamma receptor crosslinking promotes antibody-induced LILRB4 internalization and immune regulation of acute monocytic leukemia

OBJECTIVES/GOALS: The aims of this study were to: 1) determine the involvement of each Fc gamma receptor isoform in antibody-mediated crosslinking and internalization of LILRB4 in acute monocytic leukemia and 2) elucidate the role of this crosslinking and internalization in antibody-mediated immune regulation of these malignant cells. METHODS/STUDY POPULATION: To determine the involvement of Fc gamma receptors in antibody-mediated complex internalization, we generated acute monocytic leukemia cell lines with CRISPR-Cas9 knockout of each Fc gamma receptor isoform. We tested the effects of each knockout on anti-LILRB4 antibody-mediated internalization by flow cytometry and confirmed our findings with confocal microscopy. To elucidate the role of this crosslinking and internalization in immune regulation of acute monocytic leukemia, we conducted preliminary ELISA-based studies of the inflammatory signaling and cytokine release profiles of wild-type and Fc gamma receptor knockout cells treated with the LILRB4-targeting antibody. RESULTS/ANTICIPATED RESULTS: We have concluded that Fc gamma receptor I (CD64) plays a role in LILRB4 crosslinking and internalization by our anti-LILRB4 antibody and there are also contributions from Fc gamma receptor IIA (CD32A) observed in the absence of CD64 on the cell surface. Preliminary signaling studies have demonstrated that Fc gamma receptor-mediated antibody crosslinking and internalization of LILRB4 decreases anti-inflammatory signaling downstream of LILRB4 as well as pro-inflammatory signaling downstream of Fc gamma receptors, particularly in the absence of CD64 on the cell surface. The immunomodulatory effect of antibody-mediated LILRB4 crosslinking and internalization is being confirmed in follow-up signaling, cytokine release and lymphocyte activation studies. DISCUSSION/SIGNIFICANCE: This study will improve the efficacy of LILRB4-targeting antibody therapeutics for patients suffering from acute monocytic leukemia and help characterize CD64 and CD32A as potential clinical biomarkers for patients undergoing LILRB4-targeting antibody immunotherapeutic treatment, currently in first-in-human clinical trials.